I Wallentin

Publications of I Wallentin

• Assessment of effective orifice area of prosthetic aortic valves with Doppler echocardiography: an in vivo and in vitro study.

  Authors: O Bech-Hanssen, K Caidahl, I Wallentin, P Ask, B Wranne

  The Journal of thoracic and cardiovascular surgery. 09/2001; 122(2):287-95.

  OBJECTIVES: We sought to evaluate the Doppler assessment of effective orifice area in aortic prosthetic valves. The effective orifice area is a less flow-dependent parameter than Doppler gradientsOBJECTIVES: We sought to evaluate the Doppler assessment of effective orifice area in aortic prosthetic valves. The effective orifice area is a less flow-dependent parameter than Doppler gradients that is used to assess prosthetic valve function. However, in vivo reference values show a pronounced spread of effective orifice area and smaller orifices than expected compared with the geometric area. METHODS: Using Doppler echocardiography, we studied patients who received a bileaflet St Jude Medical valve (n = 75; St Jude Medical, Inc, St Paul, Minn) or a tilting disc Omnicarbon valve (n = 46; MedicalCV, Incorporated, Inver Grove Heights, Minn). The prosthetic valves were also investigated in vitro in a steady-flow model with Doppler and catheter measurements in the different orifices. The effective orifice area was calculated according to the continuity equation. RESULTS: In vivo, there was a wide distribution with the coefficient of variation (SD/mean x 100%) for different valve sizes ranging from 21% to 39% in the St Jude Medical valve and from 25% to 33% in the Omnicarbon valve. The differences between geometric orifice area and effective orifice area in vitro were 1.26 +/- 0.41 cm(2) for St Jude Medical and 1.17 +/- 0.38 cm(2) for Omnicarbon valves. The overall effective orifice areas and peak catheter gradients were similar: 1.35 +/- 0.37 cm(2) and 25.9 +/- 16.1 mm Hg for St Jude Medical and 1.46 +/- 0.49 cm(2) and 24.6 +/- 17.7 mm Hg for Omnicarbon. However, in St Jude Medical valves, more pressure was recovered downstream, 11.6 +/- 6.3 mm Hg versus 3.4 +/- 1.6 mm Hg in Omnicarbon valves (P =.0001). CONCLUSIONS: In the patients, we found a pronounced spread of effective orifice areas, which can be explained by measurement errors or true biologic variations. The in vitro effective orifice area was small compared with the geometric orifice area, and we suspect that nonuniformity in the spatial velocity profile causes underestimation. The St Jude Medical and Omnicarbon valves showed similar peak catheter gradients and effective orifice areas in vitro, but more pressure was recovered in the St Jude Medical valve. The effective orifice area can therefore be misleading in the assessment of prosthetic valve performance when bileaflet and tilting disc valves are compared.

• Important pressure recovery in patients with aortic stenosis and high Doppler gradients.

  Authors: P Gjertsson, K Caidahl, G Svensson, I Wallentin, O Bech-Hanssen

  The American journal of cardiology. 08/2001; 88(2):139-44.

  Pressure recovery has been described in aortic stenosis and may explain the difference occasionally observed between Doppler- and catheter-measured gradients. A narrow ascending aorta (AA) andPressure recovery has been described in aortic stenosis and may explain the difference occasionally observed between Doppler- and catheter-measured gradients. A narrow ascending aorta (AA) and moderately severe stenosis favors pressure recovery. The aims of this study were to investigate the degree to which these conditions are present in patients with aortic stenosis and high Doppler gradients and to evaluate the magnitude of pressure recovery. One hundred sixteen patients were examined with Doppler echocardiography before aortic valve replacement. Patients with a maximum gradient >70 mm Hg (n = 81) were included. The diameter of the AA was measured and compared with the diameter in an age- and body size-matched group of normal controls (n = 23). Pressure recovery was estimated from a previously validated equation by measuring the maximum Doppler gradient, the effective orifice area (EOA), and the diameter of the AA. The diameter of the AA was similar for patients (mean 3.0 cm, range 2.1 to 4.1) and normal controls (mean 3.0 cm, range 2.3 to 3.5). The maximum Doppler gradient was 107 mm Hg (range 71 to 170) and the EOA was 0.6 cm(2) (range 0.2 to 1.3). The calculated pressure recovery was 18 mm Hg (range 6 to 37), which gives a net gradient of 89 mm Hg (range 51 to 151). Twenty-three percent had a net gradient <70 mm Hg. A cutoff of EOA/AA diameter at >0.2 cm identified 84% of patients (16 of 19) with a net gradient <70 mm Hg. In conclusion, we found that important pressure recovery can be expected in most patients with aortic stenosis and high Doppler gradients. Pressure recovery may explain why some patients with high Doppler gradients are asymptomatic. Also, pressure recovery is a factor to consider in patients with atypical symptomatology and high Doppler gradients when one must decide on valvular replacement.

• Aortic prosthetic valve design and size: relation to Doppler echocardiographic findings and pressure recovery- an in vitro study.

  Authors: O Bech-Hanssen, K Caidahl, I Wallentin, J Brandberg, B Wranne, P Ask

  Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography. 01/2000; 13(1):39-50.

  The extent to which Doppler echocardiography information can be used in the assessment of prosthesis hemodynamic performance is still controversial. The goals of our study were to assess theThe extent to which Doppler echocardiography information can be used in the assessment of prosthesis hemodynamic performance is still controversial. The goals of our study were to assess the importance of valve design and size both on Doppler echocardiography findings and on pressure recovery in a fluid mechanics model. We performed Doppler and catheter measurements in the different orifices of the bileaflet St Jude (central and side orifices), the monoleaflet Omnicarbon (major and minor orifices), and the stented Biocor porcine prosthesis. Net pressure gradients were predicted from Doppler flow velocities, assuming either independence or dependence of valve size. The peak Doppler estimated gradients (mean +/- SD for sizes 21 to 27) were 21 +/- 10.3 mm Hg for St Jude, 18 +/- 9.3 mm Hg for Omnicarbon, and 37 +/- 14.5 mm Hg for Biocor (P <.05 for St Jude and Omnicarbon vs Biocor). The pressure recovery (proportion of peak catheter pressure) was 53% +/- 8.6% for central-St Jude, 29% +/- 8. 9% for side-St Jude, 20% +/- 5.6% for major-Omnicarbon, 23% +/- 7.4% for minor-Omnicarbon, and 18% +/- 3.6% for Biocor (P <.05 for central-St Jude and side-St Jude vs Omnicarbon and Biocor). Valve sizes (x) significantly influenced pressure recovery (y in percentage) (central-St Jude: y = 3.7x - 35.9, r = 0.88, P =.0001; major-Omnicarbon: y = 2.1x - 30.3, r = 0.85, P =.0001). By assuming dependence of valve size, Doppler was able to predict net pressure gradients in St Jude with a mean difference between net catheter and Doppler-predicted gradient of -3.8 +/- 2.5 mm Hg. In conclusion, prosthetic valve design and size influence the degree of pressure recovery, making Doppler gradients potentially misleading in both the assessment of hemodynamic performance and the comparison of one design with another. The preliminary results indicate that net gradient can be predicted from Doppler gradients.

• Influence of aortic valve replacement, prosthesis type, and size on functional outcome and ventricular mass in patients with aortic stenosis.

  Authors: O Bech-Hanssen, K Caidahl, B Wall, P Mykén, S Larsson, I Wallentin

  The Journal of thoracic and cardiovascular surgery. 08/1999; 118(1):57-65.

  OBJECTIVES: Two years after surgery for severe aortic stenosis, we prospectively evaluated the influence of aortic valve replacement, as well as valve type (mechanical or stented biologic) and size,OBJECTIVES: Two years after surgery for severe aortic stenosis, we prospectively evaluated the influence of aortic valve replacement, as well as valve type (mechanical or stented biologic) and size, on functional status, left ventricular function, and regression of mass. METHODS: Patients who received either a mechanical (n = 95) or a biologic valve (n = 42) were studied by echocardiography before the operation and after 2 years. RESULTS: The percentage of patients with severe dyspnea decreased from 53% to 13% (P =.001). The cardiac index increased from mean 2.6 L/min per square meter (95% CI: 2.48-2. 72 L/min per square meter) to 3.1 L/min per square meter (95% CI: 2. 94-3.26 L/min per square meter; P =.001). The percentage of the patients with mild-to-moderate diastolic dysfunction decreased from 43% to 18% (P =.001). The left ventricular mass index was reduced by 42.4 g (95% CI: 35-50 g; P =.001). In comparison with biologic valves of the same size, mechanical valves produced a more pronounced reduction in mass index (overall difference 21.7 g; 95% CI: 37.1-6.4 g; P =.007) and a lower mean Doppler gradient (overall difference 4 mm Hg; 95% CI: 2-6 mm Hg; P =.0002). CONCLUSIONS: Patients undergoing aortic valve replacement had an improvement in functional status, as well as systolic and diastolic left ventricular function, and a reduction in left ventricular mass index, irrespective of prosthesis size and type. Mechanical valves are somewhat less obstructive than stented bioprosthetic valves of the same size. They are also associated with a concomitantly more pronounced reduction of left ventricular mass.

• Gender differences in patients with severe aortic stenosis: impact on preoperative left ventricular geometry and function, as well as early postoperative morbidity and mortality.

  Authors: O Bech-Hanssen, I Wallentin, E Houltz, M Beckman-Suurküla, S Larsson, K Caidahl

  European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery. 02/1999; 15(1):24-30.

  OBJECTIVE: In patients with severe aortic stenosis, we studied the impact of gender on preoperative left ventricular geometry and function, as well as on early postoperative mortality and morbidity.OBJECTIVE: In patients with severe aortic stenosis, we studied the impact of gender on preoperative left ventricular geometry and function, as well as on early postoperative mortality and morbidity. METHODS: Prospective Doppler echocardiographic evaluation was performed in 99 female patients and 96 males. RESULTS: The patients had severe aortic stenosis and the mean pressure gradients were similar in females and males. Left ventricular diastolic volume adjusted for body surface area (BSA) was larger in males, 55+/-17.4 ml/m2 versus 43+/-13.1 mL/m2 (mean+/-standard deviation; P = 0.0001). The ejection fraction was similar in females (55+/-14%) and males (55+/-13%), and patients of both sexes had significantly lower stroke volume and cardiac index than healthy controls. The relative wall thickness (wall thickness/diastolic diameter ratio) was higher (P = 0.03) in females (0.47+/-0.10) than in males (0.43+/-0.10) Consequently, the diastolic diameter/wall thickness ratio (a substitute for wall tension) was higher (P = 0.02) in males (4.2+/-0.99) than in females (3.9+/-0.80). Compared with survivors, patients who died within 30 days of the operation (n = 17, 11 females) had a smaller body surface area (1.70+/-0.19 vs. 1.82+/-0.19 m2, P = 0.012), smaller left ventricular outflow tract (20.8+/-0.21 vs. 22.0+/-0.22 mm, P = 0.023), higher incidence of abnormal intraventricular flow velocity (33 vs. 8%, P = 0.018) and increased relative wall thickness (0.52+/-0.17 vs. 0.45+/-0.09 P = 0.039). Gender was of no independent importance for early mortality when age and left ventricular outflow tract diameter were accounted for. CONCLUSIONS: Cardiac adaptation to aortic stenosis seems to be influenced by gender, males presenting larger left ventricular volumes and higher wall tension. The echocardiographic findings of a narrow left ventricular outflow tract, abnormally increased intraventricular velocity and increased relative wall thickness identified patients with increased risk of early postoperative mortality. However gender had no independent impact on early postoperative outcome.

• Effects of obesity and weight loss on cardiac function and valvular performance.

  Authors: K Karason, I Wallentin, B Larsson, L Sjöström

  Obesity research. 12/1998; 6(6):422-9.

  OBJECTIVE: To study the consequences of long-standing obesity on myocardial function and valvular performance and to determine the effects of weight loss on these cardiovascular features. RESEARCHOBJECTIVE: To study the consequences of long-standing obesity on myocardial function and valvular performance and to determine the effects of weight loss on these cardiovascular features. RESEARCH METHODS AND PROCEDURES: We included 41 patients with obesity referred for weight-reducing gastroplasty, 31 patients with obesity who received dietary recommendations, and 43 lean subjects. Body weight and blood pressure were measured, and cardiac function and valvular performance were estimated echocardiographically. Left ventricular ejection fraction was used to assess systolic heart function, and the ratio of transmitral early to atrial (E/A) peak flow velocity was used as an estimate of diastolic filling. All three study groups were investigated at baseline, and the two groups with obesity were re-examined at 1-year follow-up. RESULTS: Patients with obesity had higher blood pressure, greater cardiac output, lower ejection fraction, and reduced E/A ratio, compared with lean subjects (p<0.01). Surgical treatment of obesity led to significant decreases in body weight, whereas body weight remained unchanged in the group treated with dietary recommendations (p<0.001). In the weight loss group, blood pressure and cardiac output decreased and the E/A ratio increased (p<0.001). Left ventricular ejection fraction tended to increase in the weight loss group and decrease in the obese control group (p<0.01). No significant valvular disease was observed in any of the subjects with obesity at baseline or after weight loss. DISCUSSION: We conclude that weight reduction in subjects with obesity is associated with improvements in left ventricular diastolic filling and has favorable effects on left ventricular ejection fraction. Neither obesity nor weight loss seem to promote valvular heart disease.

• Full ventricular capture indicated by the QT interval function.

  Authors: C Gottfridsson, I Wallentin, L Dernevik, H Van Rooijen, C Van Groeningen, N Edvardsson

  Pacing and clinical electrophysiology : PACE. 12/1998; 21(11 Pt 2):2171-7.

  The atrioventricular (AV) interval is critical in dual chamber (DDD) pacing in patients with hypertrophic obstructive cardiomyopathy (HOCM) to obtain full ventricular capture (FVC) with maximalThe atrioventricular (AV) interval is critical in dual chamber (DDD) pacing in patients with hypertrophic obstructive cardiomyopathy (HOCM) to obtain full ventricular capture (FVC) with maximal reduction of the left ventricular (LV) outflow gradient and optimal LV diastolic filling. We studied the relationship of FVC, fusion, spontaneous AV conduction, and the QT interval. METHODS: 11 patients with various cardiac diseases and stable AV conduction received a QT sensing Diamond, Vitatron, DDD pacemaker. Software was downloaded into the pacemaker. In the DDD pacing mode, with the QT interval measured from the ventricular pacing stimulus to the end of the T wave, the AV interval was shortened from 400 ms, in 20-ms steps, to 90 ms. At 90 ms the stimulation rate was increased by 30 beats/min and the AV interval was increased stepwise. FVC and fusion was examined on the surface ECG. RESULTS: At 400 ms interval, spontaneous AV conduction inhibited the pacemaker. Shortening the AV interval resulted in pacing with a short QT interval. Further reduction of the AV interval resulted in a longer QT interval up to a point where the QT interval became stable. This point, the bending point in the plot of measured QT interval versus shortened AV intervals, coincided with the point of FVC. The relation of the QT-AV interval plot and the point of fusion was comparable when lengthening the AV interval at a 30 beats/min faster stimulation rate. CONCLUSION: The bending point in the QT interval versus AV interval plots showed a good correlation with the FVC and fusion points observed on ECG. The results suggest that automatic discrimination between fusion and full capture using QT interval measurements may be feasible.

• Long-term Doppler echocardiographic results of aortic or mitral valve replacement with Biocor porcine bioprosthesis.

  Authors: P S Mykén, H E Berggren, S Larsson, B Roberts, I Wallentin, K Caidahl

  The Journal of thoracic and cardiovascular surgery. 11/1998; 116(4):599-608.

  OBJECTIVES: Our objectives were to evaluate the long-term bioprosthetic and cardiac functional outcome after insertion (over a 10-year period) of a new-generation porcine zero pressure-fixed BiocorOBJECTIVES: Our objectives were to evaluate the long-term bioprosthetic and cardiac functional outcome after insertion (over a 10-year period) of a new-generation porcine zero pressure-fixed Biocor bioprosthesis, as well as to determine the echocardiographic accuracy for selection of patients requiring reoperation. The long-term systematic Doppler echocardiographic assessment after valve replacement with this bioprosthesis is lacking. METHODS: Between January 1983 and January 1993, we inserted 756 Biocor prostheses in the aortic (619) or mitral (137) positions. All 51 patients who had a reoperation during the follow-up time were evaluated echocardiographically before reoperation. Additionally, 263 of 446 patients (59%) with aortic bioprostheses and 42 of 74 patients (57%) with mitral bioprostheses who were alive in January 1993 had long-term echocardiographic follow-up. RESULTS: Group A: Normally functioning bioprostheses were found in the aortic position in 242 of 263 patients and in the mitral position in 33 of 42 patients. Group B: Thirty patients had abnormal bioprosthetic function. Eleven patients had regurgitation, 3 had a combined lesion, and signs of calcification appeared in 16 patients with aortic valves, all with a peak gradient of above 60 mm Hg. Group C: Patients who had a reoperation (41 aortic and 10 mitral) within the follow-up period were followed up echocardiographically from the detection of a possible valve dysfunction until reoperation, and the findings accorded well with those at operation in 49 of 51 patients. CONCLUSIONS: These findings suggest that, during a long-term follow-up, most bioprostheses function normally, facilitating improved heart function. Abnormalities in a bioprosthesis usually develop gradually, enabling their detection by Doppler echocardiographic evaluations performed regularly or in case of any symptomatic deterioration.

• Reference Doppler echocardiographic values for St. Jude Medical, Omnicarbon, and Biocor prosthetic valves in the aortic position.

  Authors: O Bech-Hanssen, I Wallentin, S Larsson, K Caidahl

  Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography. 06/1998; 11(5):466-77.

  The objectives of the present investigation were (1) to describe Doppler echocardiographic findings for mechanical and biologic aortic valves at an early stage after operation and later in a stableThe objectives of the present investigation were (1) to describe Doppler echocardiographic findings for mechanical and biologic aortic valves at an early stage after operation and later in a stable phase and (2) to study the changes occurring between these investigations. Patients (n = 213) who received a mechanical (St. Jude Medical, Omnicarbon) or a biologic (Biocor) valve were studied by Doppler echocardiography within the first week (baseline, n = 203) and after 2 years (late, n = 172). The comparison of baseline with late investigation (mean +/- SD) showed an increase in systolic blood pressure (137 +/- 18.5 to 154 +/- 20.6 mm Hg, p = 0.0001, n = 112), reduction of heart rate (85 +/- 15.3 to 74 +/- 12.0 beats/min, p = 0.0001, n = 141) and increase in stroke volume (59 +/- 20.6 to 77 +/- 19.8 ml, p = 0.0001, n = 132). Prosthetic Doppler echocardiographic findings demonstrated a reduction in blood flow velocity in the left ventricular outflow tract (VLVOT, 1.10 +/- 0.25 to 0.96 +/- 0.23 m/sec, p = 0.0001, n = 146) reduction in peak velocity (Vmax 2.72 +/- 0.53 to 2.59 +/- 0.54 m/sec, p = 0.02, n = 150), reduction in mean pressure gradient (deltaPmean, 18.4 +/- 7.2 to 16.3 +/- 7.3 mm Hg, p = 0.004) and an increase in velocity index (Vmax/VLVOT, 2.56 +/- 0.62 to 2.67 +/- 0.60, p = 0.003, n = 144). The standard deviations of difference between baseline and late investigation expressed as percentage of mean were 25% for VLVOT, 20% for Vmax, 44% for deltaPmean, and 25% for velocity index. In conclusion, this large reference base provides data that should be useful for the clinician evaluating patients with prosthetic valves early after valve replacement as well as at a later stage. When valve dysfunction is suspected a previous investigation for comparison is helpful, and our data describe the changes that normally may be seen between an early baseline and a late investigation.

• Effects of obesity and weight loss on left ventricular mass and relative wall thickness: survey and intervention study.

  Authors: K Karason, I Wallentin, B Larsson, L Sjöström

  BMJ (Clinical research ed.). 11/1997; 315(7113):912-6.

  OBJECTIVES: To investigate the consequences of longstanding obesity on left ventricular mass and structure and to examine the effects of weight loss on these variables. DESIGN: Cross sectional surveyOBJECTIVES: To investigate the consequences of longstanding obesity on left ventricular mass and structure and to examine the effects of weight loss on these variables. DESIGN: Cross sectional survey and controlled intervention study. SETTING: City of Gothenburg and surrounding areas. Sweden. SUBJECTS: 41 obese patients treated with weight reducing gastric surgery, 31 obese patients treated conventionally, and 43 non-obese subjects. MAIN OUTCOME MEASURES: Changes in left ventricular mass and relative wall thickness. RESULTS: Obese patients had higher blood pressure, greater left ventricular mass, and increased relative wall thickness than did matched non-obese control subjects. Obese subjects treated with gastric surgery had a substantial weight loss and a significant reduction in all variables when compared with conventionally treated obese subjects. Univariate and multivariate analysis of pooled data from the two groups of obese subjects showed that changes in relative wall thickness and left ventricular mass were more closely related to the change in weight than to the concomitant change in blood pressure. CONCLUSIONS: Structural heart abnormalities occurring in conjunction with obesity diminish after weight loss. The regression in these structural aberrations is better predicted by the weight loss than by the accompanying reduction in blood pressure. To prevent or improve abnormalities of heart structure in obese people, weight control should be the primary goal; it should be regarded as at least as important as regulating blood pressure.

• Reduced left ventricular hypertrophy in type 1 diabetic patients with end-stage renal failure. A comparison between groups investigated 1977-80 and 1991-93.

  Authors: O Bech-Hanssen, I Wallentin, O Larsson, G Nyberg

  Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. 09/1996; 11(8):1547-52.

  BACKGROUND: During the last decade, control of hypertension, oedema, anaemia, uraemia, and blood glucose has improved in patients with diabetic nephropathy. We have investigated whether this hasBACKGROUND: During the last decade, control of hypertension, oedema, anaemia, uraemia, and blood glucose has improved in patients with diabetic nephropathy. We have investigated whether this has influenced cardiac function at the time of end-stage renal failure. STUDY DESIGN: Echocardiographic investigations were performed in 26 type 1 diabetic patients evaluated for kidney transplantation and the results compared with those obtained in healthy controls and in a similar group of patients investigated in 1977-1980. RESULTS: Blood pressure was 153 +/- 21/85 +/- 12 mmHg versus 174 +/- 17/91 +/- 9 (recent group versus early group). The left ventricular (LV) diameter index, a measure of volaemia, was increased in systole and diastole in the early but not in the recent group. Both groups had LV hypertrophy, but this was much less pronounced in the recent group; posterior wall thickness was 1.1 +/- 0.16 cm versus 1.3 +/- 0.26 cm (P = 0.0001) and LV mass index 132 +/- 43 g/m2 versus 166 +/- 44 g/m2 (P = 0.009). Blood pressure correlated significantly with indices of LV hypertrophy in the recent group. Systolic function was normal in both groups but diastolic function was disturbed in both and to the same extent, atrial systole contributing by 27 +/- 14% to ventricular filling. CONCLUSION: Better treatment of hypertension, fluid overload, and uraemia has led to less pronounced LV hypertrophy. The remaining correlation with blood pressure suggests that more could be gained by intensified antihypertensive treatment.

• Changes in early and late diastolic filling patterns induced by long-term adrenergic beta-blockade in patients with idiopathic dilated cardiomyopathy.

  Authors: B Andersson, K Caidahl, A Di Lenarda, S E Warren, F Goss, A Waldenström, S Persson, I Wallentin, A Hjalmarson, F Waagstein

  Circulation. 09/1996; 94(4):673-82.

  BACKGROUND: beta-Blockers have been used in patients with idiopathic dilated cardiomyopathy to improve cardiac performance and theoretically would be beneficial to diastolic function. However, thereBACKGROUND: beta-Blockers have been used in patients with idiopathic dilated cardiomyopathy to improve cardiac performance and theoretically would be beneficial to diastolic function. However, there are few reports on changes in diastolic function during chronic pharmacological treatment of congestive heart failure. METHODS AND RESULTS: The present study was a substudy in the international Metoprolol in Dilated Cardiomyopathy Trial. Transmitral Doppler echocardiography was used to evaluate diastolic function in 77 patients randomly assigned to placebo (n = 37) or metoprolol (n = 40). The patients were treated for 12 months. Changes in Doppler flow variables in the metoprolol group implied a less restrictive filling pattern, expressed as an increase in E-wave deceleration time (placebo, 185 +/- 126 to 181 +/- 64 ms; metoprolol, 152 +/- 63 to 216 +/- 78 ms; P = .01, placebo versus metoprolol). Maximal increase in deceleration time had occurred by 3 months, whereas systolic recovery was achieved gradually and maximal effect was seen by 12 months of treatment. Although deceleration time was correlated to heart rate at baseline, changes in deceleration time were not significantly correlated to changes in heart rate during treatment. CONCLUSIONS: During the first 3 months of treatment, maximal effects on diastolic variables were reached, whereas the most prominent effect on systolic function was seen late in the study. It is suggested that effects on diastolic filling account for subsequent later myocardial systolic recovery. The E-wave deceleration time, which in recent studies has been shown to be a powerful predictor of survival, was significantly improved in the metoprolol-treated patients.

• Preoperative echocardiographic prediction of small prosthesis size for aortic valve replacement.

  Authors: O Bech-Hanssen, K Caidahl, P S Mykèn, U Kjellman, S Larsson, I Wallentin

  The Journal of heart valve disease. 04/1996; 5(2):128-35.

  BACKGROUND AND AIMS OF THE STUDY. Prosthesis size is known to have an effect on long term outcome after heart valve replacement. We evaluated 115 patients subjected to aortic valve replacement toBACKGROUND AND AIMS OF THE STUDY. Prosthesis size is known to have an effect on long term outcome after heart valve replacement. We evaluated 115 patients subjected to aortic valve replacement to assess the ability by preoperative echocardiography to identify patients having small aortic roots and thereby likely to receive a small prosthesis (size 19 or 21), previously shown to be associated with a worse prognosis. METHODS. From an initial part of the study (Group A), comprising 67 patients, we evaluated the influence of image quality on the accuracy for prediction of patients receiving a small prosthesis. In a second series of 48 patients (Group B), we tested the predictive value of various limits of aortic annulus diameter to define patients at risk of receiving a small prosthesis. RESULTS. The measurement of aortic annulus diameter in Group A gave a reasonable correlation to subsequent prosthetic dimension (r = 0.73, n = 59). However, there was a considerable variation of echocardiographic aortic annulus diameter among patients receiving prostheses of the same size. In Group B, an aortic annulus diameter of < or = 22 mm correctly identified 10 of 13 patients receiving a small prosthesis (sensitivity 77%). Twenty-two of 25 patients (88%) with an aortic annulus diameter > 22 mm received a large prosthesis. CONCLUSIONS. We conclude that the echocardiographic measurement of the aortic annulus diameter is a fairly sensitive method to identify patients receiving a small prosthesis. However, the predictive accuracy is dependent upon training as well as image quality. Furthermore, the value of planning in advance the type of prosthesis, annuloplasty or homograft for aortic valve replacement remains to be shown.

• Mechanical versus biological valve prosthesis: a ten-year comparison regarding function and quality of life.

  Authors: P S Mykén, K Caidahl, P Larsson, S Larsson, I Wallentin, H E Berggren

  The Annals of thoracic surgery. 09/1995; 60(2 Suppl):S447-52.

  To determine the long-term outcome of biological and mechanical heart valve prostheses, we compared the Biocor, a new generation of porcine bioprosthesis, with the St. Jude Medical mechanicalTo determine the long-term outcome of biological and mechanical heart valve prostheses, we compared the Biocor, a new generation of porcine bioprosthesis, with the St. Jude Medical mechanical prosthesis. One hundred consecutive patients operated on between 1983 and 1985 with the Biocor in the aortic, mitral, or both positions (without concomitant cardiac procedures) were followed until January 1993, together with 100 matched patients implanted with the St. Jude valve. The mean age was 66 and 67 years, respectively. The follow-up was 100% complete. Valve-related mortality differed significantly, with a freedom rate of 80.7% +/- 9.0% for the St. Jude group and 97.7% +/- 1.6% for the Biocor group. There were few thromboembolic events, with no significant difference between the groups. Anticoagulant-related hemorrhage occurred almost exclusively in the St. Jude group (2.3%/patient-year), and reoperations were required almost exclusively in the Biocor group (1.8%/patient-year). The occurrence of all valve-related complications (mortality plus morbidity) differed markedly, with an actuarial freedom at 10 years of 55.8% +/- 9.8% for St. Jude and 80.0% +/- 4.4% for the Biocor. Quality of life and echocardiographic measurements did not differ significantly between the groups. We conclude from this study that the long-term performance of the Biocor and St. Jude are comparable, even though valve-related complications tended to be fewer in the Biocor group, with a significantly lower incidence of valve-related death.

• [Superior vena cava syndrome. Surgery of thrombosis of the right atrium immediately after intravenous fluid therapy is preferable]

  Authors: L Dernevik, E Houltz, C Lamm, I Wallentin

  Läkartidningen. 04/1992; 89(13):1083-4.

• Left ventricular function in kidney transplanted type 1 diabetic patients with and without a pancreas transplant.

  Authors: G Nyberg, O Bech-Hanssen, I Wallentin, M Olausson, I Blohmé

  Transplantation proceedings. 03/1992; 24(1):349.

• Adenosine infusion to patients with ischaemic heart disease may provoke left ventricular dysfunction detected by echocardiography.

  Authors: A Edlund, P Albertsson, K Caidahl, H Emanuelsson, I Wallentin

  Clinical physiology (Oxford, England). 10/1991; 11(5):477-88.

  Infusion of the endogenous vasodilator adenosine to patients with ischaemic heart disease (IHD) frequently provokes myocardial ischaemia, possibly caused by a coronary steal. The aim of this studyInfusion of the endogenous vasodilator adenosine to patients with ischaemic heart disease (IHD) frequently provokes myocardial ischaemia, possibly caused by a coronary steal. The aim of this study was to detect the occurrence and incidence of disturbances in left ventricular (LV) wall motion and Doppler indices of altered LV function during infusion of adenosine. Thirty-seven patients (six female) aged 37-74 years with IHD, verified by coronary angiography, were given up to 200 micrograms kg-1 min-1 (mean 155 +/- 5) adenosine i.v. for 18 +/- 1 min. LV wall motion was monitored by two-dimensional echocardiography (2D-echo). Doppler spectral signal was obtained from the mitral blood flow. All but six of the patients experienced angina pectoris of habitual character in connection with the adenosine infusion. Heart rate increased by 22 +/- 1 beats min-1, systolic blood pressure was unchanged, but diastolic blood pressure decreased slightly. 2D-echo revealed severe regional LV wall motion disturbances already in the basal state in 17 patients. During infusion of adenosine, these abnormalities were aggravated and disturbances also occurred in another 15 patients. Thus, adenosine increased the sensitivity for IHD in this selected material from 49 to 89%. In all, the mean index of wall motion abnormalities increased from 5.1 +/- 1.1 to 10.1 +/- 1.4 (P less than 0.001). The diastolic LV filling characteristics, as evaluated by the Doppler A/E ratios, were of limited value for determination of IHD grade. It is concluded that infusion of adenosine to patients with IHD frequently elicits myocardial ischaemia with disturbances in LV function, and offers an alternative to exercise for stress echocardiography.

• Echocardiographic findings in kidney transplanted type 1 (insulin-dependent) diabetic patients with and without a pancreas transplant.

  Authors: G Nyberg, O Bech-Hanssen, M Olausson, I Wallentin

  Diabetologia. 09/1991; 34 Suppl 1:S128-30.

  Echocardiography with Doppler recordings was carried out in 14 Type 1 (insulin-dependent) diabetic recipients of pancreas and kidney transplants and in 14 Type 1 diabetic kidney transplanted controlEchocardiography with Doppler recordings was carried out in 14 Type 1 (insulin-dependent) diabetic recipients of pancreas and kidney transplants and in 14 Type 1 diabetic kidney transplanted control patients, matched for age, sex, duration of diabetes, extent of other late complications, time since transplantation, dose of prednisolone, and renal function. HbA1c was 5.5 +/- 0.6 vs 8.7 +/- 1.4% (pancreas transplanted vs kidney only). Both groups had a slight increase in interventricular septum thickness. Left ventricular mass was equal. The ejection fraction as a measure of systolic function was normal and equal, 0.71 +/- 0.05 vs 0.69 +/- 0.07. Diastolic function was also equal in two out of three parameters, isovolumic relaxation time and deceleration time. The A/E ratio, however, tended to be lower in the pancreas transplanted group, 0.94 +/- 0.20 vs 1.06 +/- 0.18 (p = 0.04). This indicates more frequent occurrence of impaired diastolic filling in the recipients of kidney only. Follow-up will show whether diastolic dysfunction increases and may be related to the increased cardiovascular mortality in kidney transplanted Type 1 diabetic patients.

• Long-term beta-blockade in dilated cardiomyopathy. Effects of short- and long-term metoprolol treatment followed by withdrawal and readministration of metoprolol.

  Authors: F Waagstein, K Caidahl, I Wallentin, C H Bergh, A Hjalmarson

  Circulation. 10/1989; 80(3):551-63.

  To evaluate the short- and long-term effects of beta-adrenergic blockade (metoprolol) as well as the reaction to withdrawal and readministration of metoprolol in severe heart failure, 33 patients (25To evaluate the short- and long-term effects of beta-adrenergic blockade (metoprolol) as well as the reaction to withdrawal and readministration of metoprolol in severe heart failure, 33 patients (25 men and eight women; mean age, 47.6 +/- 14.0 years) with dilated cardiomyopathy were studied by right and left heart catheterization, right ventricular biopsy, two-dimensional and Doppler echocardiography, and external pulse recordings. Twenty-six of 33 patients survived more than 6 months, and 24 of the 26 patients improved their functional class (from mean 3.3 to 1.8, p less than 0.0001). These 24 patients were subjected to withdrawal of metoprolol until the number of symptoms increased and deterioration occurred as observed noninvasively (group 1, n = 16), whereas the eight patients did not deteriorate during a 12-month period (group 2). During long-term treatment with metoprolol, there was an increase in ejection fraction from 0.24 to 0.42 (p less than 0.0001), whereas there was a decrease in the left ventricular (LV) end-diastolic dimension (from 7.3 to 6.4 cm, p less than 0.0001), in the grade of mitral regurgitation (from 1.7 to 0.4, p less than 0.0001), and in the grade of tricuspid regurgitation (from 0.6 to 0.05, p less than 0.007). There was a decrease in pulmonary wedge pressure (from 23.8 to 10.7 mm Hg, p less than 0.0001), LV end-diastolic pressure (from 24.1 to 13.4 mm Hg, p less than 0.002), and systolic vascular resistance (from 1,782 to 1,499 dynes/sec/cm, p less than 0.04). There was an increase in systolic blood pressure (from 116 to 132 mm Hg, p less than 0.003), cardiac index (from 2.17 to 2.58 l/min/m2, p less than 0.005), and LV stroke work index (from 31 to 65 g.m/m2, p less than 0.0001). During withdrawal of metoprolol, the heart rate and left atrial dimension increased (p less than 0.0001), whereas ejection fraction decreased (p less than 0.0001). The 12 (of 16) patients in group 1 who survived the withdrawal period had metoprolol readministered, and subsequently, ejection fraction increased (from 0.23 to 0.33, p less than 0.002). Patients had a low number of ventricular beta-adrenergic receptors compared with healthy control subjects (30.3 +/- 2.9 vs. 97.4 +/- 8.7 fmol/mg protein, p less than 0.001), but long-term treatment with metoprolol caused a moderate up-regulation (from 30.3 +/- 2.9 to 49.0 +/- 7.1 fmol/mg protein, p less than 0.05), which may facilitate a more normal response to sympathetic stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

• [Extracorporeal circulation in severe failure in a patient with transplanted heart--waiting for a new heart]

  Authors: A Westerlind, S Höyer, I Wallentin, K Caidahl, E Berglin, N Edvardsson

  Läkartidningen. 04/1989; 86(11):960-2.