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ABSTRACT: Pulmonary artery catheterization is almost uniformly used nowadays in cardiac surgery. Although rare, rupture of the pulmonary artery following catheterization is highly lethal. This review examines ways of avoiding its occurrence and means of improving outcomes in case of rupture.
Annales de Chirurgie 11/2006; 131(8):426-30. · 0.35 Impact Factor
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ABSTRACT: Echocardiography is the modality of choice for the noninvasive recognition of vegetations and abscesses that complicate endocarditis. Vegetation size is highly variable, and it has been suggested that large vegetations are related to a more complicated course. The case we present is unusual in that the echocardiographically detected vegetation was very large, highly mobile, and caused severe obstruction of the left ventricular outflow tract, which led to impaction and cardiac arrest.
Journal of the American Society of Echocardiography 10/2000; 13(9):869-72. · 3.71 Impact Factor
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ABSTRACT: While radiofrequency catheter ablation is very effective, it does not allow for prediction of success prior to full delivery of the energy. We investigated the use of cryoablation using a new catheter on the AV node to determine (1) if a successful site might be identified prior to the ablation itself, and (2) the parameters of cryoablation of the AV node using a new cryocatheter. In eight dogs, the cryoablation catheter was advanced to the AV node to produce transient high degree AV block by lowering the temperature to a minimum of -40 degrees C (ice mapping). Transient high degree AV node block was obtained in seven of eight animals at a mean temperature of -39.9 +/- 11.6 degrees C. No significant pathological modification was found in all animals but one and, in all cases, electrophysiological parameters of the AV node measured before, 20 minutes, 60 minutes, and up to 56 days after cryoapplication were not significantly different. In the 12 other dogs, after ice mapping, cryoablation of the AV node was attempted with a single freeze-thaw cycle in 6 dogs (group I) and a double freeze-thaw cycle in the other 6 dogs (group II). Chronic complete AV block was obtained in only one animal in group I compared to all animals in group II. Ablation of the AV node is effective with a double freeze-thaw cycle using a percutaneous catheter cryoablation system. Ice mapping of the area allows for identification of the targeted site.
Pacing and Clinical Electrophysiology 11/1999; 22(10):1488-98. · 1.35 Impact Factor
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ABSTRACT: A 72-year-old woman presented to hospital with rapidly progressive dyspnea and chest pain on exertion. Physical findings included a grade 3/6 systolic murmur increased by the Valsalva manoeuvre. Transthoracic echocardiography revealed concentric left ventricular hypertrophy, systolic anterior motion of the mitral valve and critical dynamic outflow tract obstruction. The myocardium was strikingly heterogeneous with hyperdynamic left ventricular systolic function. Laboratory findings included severe hypercalcemia secondary to primary hyperparathyroidism. The patient's outcome was unfavourable with nephrogenic diabetes insipidus, pancreatitis, shock, severe acidosis and death. Postmortem examination confirmed the presence of severe concentric left ventricular hypertrophy, a narrowed left ventricular outflow tract and localized endocardial fibrosis of the left interventricular septum. Microscopic findings showed diffuse calcium deposits of the myocardium, coronary arteries, kidneys and lungs. This appears to be the first report of two-dimensional and Doppler echocardiographic findings in hypercalcemic cardiomyopathy mimicking obstructive hypertrophic cardiomyopathy.
The Canadian journal of cardiology 12/1998; 14(11):1397-400. · 3.36 Impact Factor
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ABSTRACT: We investigated the feasibility of using cryogenic technology in an electrode catheter for percutaneous ablation of cardiac tissue. Despite its high success rate, radiofrequency catheter ablation has important limitations especially with regards to the treatment of ventricular arrhythmias associated with a chronic scar. Arrhythmia surgery experience has shown that freezing with a hand held probe can permanently ablate the arrhythmogenic substrate of ventricular tachycardia associated with an old scar. Moreover, cryosurgery also allows for reversible "ice mapping," in which the area likely responsible for the arrhythmia can be evaluated by suppressing its electrophysiologic properties prior to the creation of an irreversible state. A new steerable cryoablation catheter using Halocarbon 502 as a refrigerant was utilized in six dogs. Serial cryoapplications were performed in the right and left ventricles. In two dogs, we attempted reversible ice mapping of the AV node. Pathological evaluation of the lesions was done acutely in all the animals. Forty-two cryoapplications were delivered at a mean temperature of -45 +/- 9.8 degrees C. No lesion was found at pathological evaluation for 16 cryoapplications which did not achieve a temperature of less (colder) than -30 degrees C. The remaining applications resulted in 26 lesions which were hemorrhagic and sharply demarcated from normal myocardium. Histological evaluation revealed contraction band necrosis. Reversible ice mapping of the AV node was successfully achieved in two animals. Cryoablation is feasible using an electrode catheter with multiple electrodes. This technology has the potential to allow for reversible ice mapping to confirm a successful ablation target before definitive ablation.
Journal of Interventional Cardiac Electrophysiology 10/1998; 2(3):285-92. · 1.17 Impact Factor
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ABSTRACT: Mycotic pseudoaneurysms of upper extremities are an infrequent complication of endocarditis. We describe a case of mycotic pseudoaneurysm of the superficial palmar arch in a patient who had acute bacterial endocarditis. We discuss operative and pathologic findings and briefly review the literature on the subject.
Journal of Vascular Surgery 12/1997; 26(5):891-4. · 3.21 Impact Factor
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ABSTRACT: Pulmonary hypertension is associated with endothelial dysfunction that may mediate or contribute to the disease process; among those abnormalities is an increase in circulating endothelin-1 levels. We investigated the effect of the orally active endothelin A receptor antagonist LU 135252 (LU) on the development of monocrotaline (MCT)-induced pulmonary hypertension and endothelial metabolic dysfunction. Rats were assigned to four groups by receiving a single dose of MCT or saline, followed by once-daily gavage with LU (50 mg/kg) or saline for 3 weeks. Plasma immunoreactive endothelin-1 levels doubled after MCT and were unaffected by LU therapy. The MCT-induced increase in right ventricular systolic pressure (72.5 +/- 15.9 mmHg) and hypertrophy (right ventricle/[left ventricle plus septum weight]; 0.58 +/- 0.08) were reduced by LU to 42.7 +/- 8.5 mmHg (P < .01) and 0.42 +/- 0.05 (P < .01), respectively. LU, however, did not modify MCT-induced pulmonary artery medial hypertrophy. Pulmonary vascular endothelial metabolic activity was evaluated in isolated lungs by measuring endothelium-bound angiotensin-converting enzyme activity using a synthetic angiotensin-converting enzyme substrate, 3H-benzoyl-phenylalanly-glycyl-proline. MCT reduced fractional 3H-benzoyl-phenylalanly-glycyl-proline hydrolysis (0.488 +/- 0.051, P < .01) which was normalized by LU therapy (0.563 +/- 0.050). LU treatment alone had no significant effect on any of these parameters. We conclude that the endothelin A antagonist LU reduces MCT-induced pulmonary hypertension and right ventricular hypertrophy and restores endothelial metabolic function. These results support the development of endothelin antagonists for the treatment of pulmonary hypertension and associated endothelial metabolic abnormalities.
Journal of Pharmacology and Experimental Therapeutics 09/1997; 282(3):1312-8. · 3.83 Impact Factor
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American Heart Journal 07/1996; 131(6):1221-3. · 4.65 Impact Factor
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ABSTRACT: A prospective, randomized clinical study involving 34 patients undergoing heart transplantation compared myocardial preservation of donor hearts maintained with continuous reperfusion with retrograde warm blood cardioplegia during surgical implantation versus the standard cold topical irrigation.
Hearts in both groups were arrested with a standard crystalloid solution and maintained in a cold saline solution during transportation. In the retrograde group, cardioplegia was administered through a catheter in the coronary sinus during surgical implantation. An average of 471 +/- 30 mL of hyperkalemic crystalloid solution diluted 1:4 in warm blood from the oxygenator was infused. In the standard group, the heart was kept cold by topical irrigation of cold saline solution and was reperfused only when the ascending aorta was unclamped.
Preoperative characteristics of donors and recipients were similar in the two cohorts. Ischemic time average 139 +/- 12 minutes in the retrograde group compared with 130 +/- 11 minutes in the standard group (p = 0.57). Cardiopulmonary bypass time averaged 89 +/- 4 minutes in the retrograde group and 110 +/- 12 minutes in the standard group (p = 0.12). Defibrillation at reperfusion was performed in 4 patients (4/17, 24%) in the retrograde group and 12 patients (12/18, 67%) in the standard group (p = 0.01). There were no deaths in the retrograde group (0/17), whereas in the standard group, 3 patients (3/17) died of early graft failure (p = 0.11). Four early graft failures occurred in the standard group (p = 0.06). Two patients (2/17, 12%) were weaned from bypass with ventricular assist devices in the standard group. The number of subendocardial necrotic cells in the first two weekly endomyocardial biopsy specimens averaged 2.7 +/- 0.8 cells/mm2 in the retrograde group and 5.9 +/- 2.4 cells/mm2 in the standard group (p = 0.12).
Retrograde warm blood reperfusion appears to improve the initial recovery of transplanted hearts. The technique is easy to use and may be a useful approach to graft protection during surgical implantation.
The Annals of Thoracic Surgery 06/1996; 61(5):1310-4; discussion 1314-5. · 3.74 Impact Factor
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ABSTRACT: Looking for a coronary artery restenosis model closer to human pathology, a protocol of balloon injury/reinjury (plaque of dilatation) in swine coronary artery was designed. Pig coronary arteries (n = 24) were dilated for this study: 12, group 1, once (sacrifice at 10.0 +/- 2.2 weeks); 6, group 2, twice at 2-wk intervals (sacrifice at 5.2 +/- 0.2 wk); 6, group 3, twice at 4-wk intervals (sacrifice at 9.3 +/- 1.9 wk). A single overdilatation resulted in an eccentric neointimal hyperplasia representing half of the wall area (group 1, 45.6 +/- 5.1%). In animals (groups 2 and 3) subjected to redilatation, fracture length, ratio of fracture length to internal elastic lamina (IEL) circumference, and neointimal hyperplasia response were similar to those observed in group 1. In group 3, the shape of the lesion appeared more concentric and the fracture of the IEL more fragmented than in group 1. Although this model of injury/reinjury did not lead to more severe intimal hyperplasia, performing a second angioplasty at the same site did lead to a more concentric intimal response, related to multiple fractures of the IEL.
Catheterization and Cardiovascular Diagnosis 06/1996; 38(1):44-9.
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ABSTRACT: To establish the effects of acute rejection on coronary artery endothelial reactivity in a canine model of heart transplantation, we submitted seven mongrel dogs to heterotopic heart transplantation without immunosuppression for a period of 7 days. At harvesting, all transplanted hearts displayed a grade IV histologic rejection. Compared with native heart, the endothelium-dependent relaxation of the coronary arteries from the graft displayed an increased sensitivity to serotonin, a decreased sensitivity to thrombin, and no change in the response to acetylcholine and adenosine diphosphate; endothelium-independent relaxation to sodium nitroprusside was not affected. Therefore, in the canine heterotopic heart transplant model, acute rejection has no effect on endothelium-independent relaxation of coronary arteries but affects endothelium-dependent relaxation in a receptor-specific manner.
The Journal of Heart and Lung Transplantation 05/1996; 15(4):404-8. · 4.33 Impact Factor
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ABSTRACT: Coronary artery disease is a common complication of cardiac transplantation threatening long-term survival and its management is not well defined. Percutaneous transluminal coronary angioplasty has been proposed as a palliative and exceptional technique in some patients with limited lesions. Of 145 patients undergoing cardiac transplantation between April 1983 and January 1994, 7 underwent 10 coronary angioplasty procedures. The majority was performed in asymptomatic patients, 4 for angigraphic abnormalities alone and 3 for documented painless ischaemia. Primary angiographic success was obtained in 90% (9 out of 10) of lesions. Complication included one acute occlusion and one arteriovenous fistula. Three patients died, 1, 8 and 10 months after angioplasty. After an average of 24 months' follow-up, 3 (out of 7) patients had no cardiac events (myocardial infarction, second angioplasty, second transplantation or death). A multicentre prospective controlled trial is necessary to assess the impact of this procedure on graft and patient survival.
Archives des maladies du coeur et des vaisseaux 11/1995; 88(10):1375-80. · 0.40 Impact Factor
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ABSTRACT: Physiopathologic events after arterial injury are largely influenced by blood element reactions with the injured surface. To determine acute arterial reactivity to injury, simultaneous chromium 51-labeled platelet deposition and indium 111-labeled neutrophil adhesion were quantified at the site of different degrees of carotid arterial injury by balloon dilatation in 21 normal pigs. The degree of vasoconstriction distally to the dilated areas was also quantified angiographically. Arteries were classified histologically as (1) uninjured with intact endothelium; (2) mildly injured with endothelial desquamation; or (3) deeply injured with lesions extending beyond internal elastic lamina, exposing the media. We found that, compared to mild injury, deep injury was associated with greater platelet deposition (38.2 +/- 5.7 x 10(6)/cm2 vs 7.8 +/- 0.9 x 10(6)/cm2; p < 0.05), neutrophil adhesion (30.6 +/- 4.1 x 10(4)/cm2 vs 10.2 +/- 2.9 x 10(4)/cm2; p < 0.05), and vasoconstrictive response (45.5% +/- 3.2% vs 26.7% +/- 2.8%; p < 0.05). Although distally to both types of injuries, noninjured arterial segments with intact endothelium were thromboresistant to platelet deposition, neutrophil adhesion to intact endothelium was much higher after deep injury (2.2 +/- 0.4 x 10(4)/cm2) compared to mild injury (0.36 +/- 0.1 x 10(4)/cm2; p < 0.05). Like platelet deposition, neutrophil adhesion is influenced by the severity of arterial injury; both may therefore be implicated in thrombogenesis and vascular responsiveness after arterial injury in vivo.
American Heart Journal 04/1995; 129(3):445-51. · 4.65 Impact Factor
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ABSTRACT: Chronic rejection has been linked to premature coronary atherosclerosis in heart transplantation and may be related to altered vascular reactivity. However, the effect of acute rejection on coronary reactivity remains uncertain. To evaluate this aspect, coronary artery reactivity was studied during acute rejection in a canine model of heart transplantation. Two groups of mongrel dogs (n = 7) (20 to 30 kg) underwent heterotopic heart transplantation (cervical position), and received either no treatment (noTx) or cyclosporine (CyA), 10 mg/kg/day. On day 7, recipient native (NH) and grafted hearts (GH) were harvested and 4-mm rings from the circumflex coronary artery were studied in organ chambers for endothelium and smooth muscle reactivity. At the harvesting, GHnoTx displayed a grade IV/IV histologic rejection while GHCyA (CyA dosage 250-350 nM) reached grade IIIa-IV. Intimal hyperplasia was found in coronary arteries of treated and non-treated GH [4/7 (noTx) vs 3/7 (CyA)]. Endothelium-dependent relaxation to thrombin was impaired in GH compared to NH and was not influenced by CyA treatment [EC50 (-log M): GHnoTx: 1.12 +/- 0.18 vs NHnoTx: 1.67 +/- 0.16 (p = 0.06); GHCyA: 0.99 +/- 0.22 vs NHCyA: 1.64 +/- 0.09 (p = 0.02)]. Conversely, endothelium-dependent relaxation to 5-hydroxytryptamine (5-HT) was enhanced in both CyA-treated and noTx groups [EC50 (-log M); GHnoTx: 5.96 +/- 0.12 vs NHnoTx: 5.54 +/- 0.14 (p = 0.046); GHCyA: 6.65 +/- 0.19 vs NHCyA: 5.66 +/- 0.16 (p = 0.004)]. A facilitating effect of CyA on 5-HT was also seen in GH [GHnoTx vs GHCyA (p = 0.01)], suggesting a CyA intrinsic effect. Responses to acetylcholine and adenosine diphosphate were similar in all groups as well as endothelium-independent relaxation to sodium nitroprusside and contractile response to KCl and PGF2 alpha. We conclude that, in our model, acute rejection does not specifically impair cGMP-mediated relaxation but affects in a receptor-specific manner the endothelium-dependent relaxation. CyA did not prevent these effects but furthermore appeared to enhance the coronary endothelial sensitivity to 5-HT.
Annales de Chirurgie 02/1995; 49(8):735-42. · 0.35 Impact Factor
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ABSTRACT: The purpose of this study was to describe the mechanism and determine predictive factors of mitral valve rupture requiring valve replacement following percutaneous mitral commissurotomy. Of the 350 consecutive patients treated by balloon mitral commissurotomy, the procedure was not completed in 16, and 11 developed acute severe mitral regurgitation requiring valve replacement: seven cases of anterior leaflet rupture, three cases of posterior leaflet rupture and one case of anterior chordal surface. These 27 group I patients were compared to the remaining 323 (group II) in whom the procedure was completed. The 11 excised valves were evaluated by an experienced pathologist. Eight of the 11 patients had an echocardiographic score < 8 (mean score 6.5 +/- 1), no valvular calcification at X-ray and double balloon percutaneous mitral commissurotomy. Microscopy in six patients showed focal fibrous thickening at the site of the rupture but no calcification. One patient developed severe mitral regurgitation due to chordal rupture with an Inoue balloon. The two remaining patients had an echo score of ten and valve calcification on X-ray. Microscopy revealed severe homogeneous chronic rheumatic mitral disease. In one of these two patients, leaflet rupture was related to an 'oversized balloon' (2 x 19 mm + 15 mm). Statistical analysis showed only echo score differences between the two groups (6.9 +/- 1.4 in group I vs 8.2 +/- 1.6 in group II, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)
European Heart Journal 02/1995; 16(1):43-8. · 10.48 Impact Factor
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ABSTRACT: Of a total of 133 patients who underwent heart transplantation, 16(12%) had pericardial and mediastinal complications. Non-infectious pericardial complications, pericardial effusion and constriction were noted in ten patients, and infectious pericarditis or mediastinitis in six. Cardiac echocardiography, catheterization and magnetic resonance imaging were useful in assessing these problems. All patients underwent surgical treatment, pericardial drainage, pericardectomy or muscle flap closure. Twelve (75%) of these 16 patients are long-term survivors. In conclusion, pericardial and mediastinal complications are common after heart transplantation, and aggressive surgical treatment is most often effective in their control.
Cardiovascular Surgery 07/1994; 2(3):395-7.
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ABSTRACT: Mediastinitis-related right ventricular rupture is an unusual but potentially life-threatening complication of cardiac operations. Between January 1981 and December 1990, a total of 10,182 patients underwent heart operations for ischemic, valvular, and congenital heart disease at the Montreal Heart Institute. Forty-eight patients (0.5%) had postoperative mediastinitis necessitating surgical exploration and sternal debridement. The mediastinum was left open for daily irrigation with povidone-iodine and chest reconstruction was postponed. During treatment, seven patients (0.07%) had right ventricular rupture necessitating immediate surgical repair. All had ischemic heart disease before the operation. There were five women and two men, ages ranging from 52 to 65 years (mean 58 +/- 5 years). Surgical repair consisted of autologous patch covered with omentoplasty assisted with cardiopulmonary bypass. Two patients died, one during the operation of massive hemorrhage and the other 10 days after the operation of uncontrolled sepsis. Five patients survived 2 to 29 months (mean 23 +/- 10 months) after right ventricular rupture, with an overall survival of 71%. Obesity was more frequent in the patients with right ventricular rupture and was found to be a significant risk factor (multivariate analysis, p < 0.05, relative risk 3.22). Histologic examination of the right ventricle in the patient who died after a successful repair revealed fatty infiltration of the right ventricular wall. This may have predisposed the patient toward ventricular rupture. In conclusion, right ventricular rupture, an unusual event in heart surgery, is related to open sternal debridement. Favorable outcome of this complication depends on immediate surgical management, autologous repair, and the use of omentoplasty.
Journal of Thoracic and Cardiovascular Surgery 01/1994; 106(6):1036-9. · 3.41 Impact Factor
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ABSTRACT: To investigate the mechanisms of restenosis and detect useful interventions to prevent it, reliable quantitative measurements must be evaluated. Coronary arteries of domestic and minipigs (n = 18) were mechanically injured by balloon overstretching and killed at different intervals (2 to 25 weeks) after quantitative angiographic analysis. Morphometric measurements evaluated intimal hyperplasia at 0.59 +/- 0.42 mm without relation to artery size or balloon/artery ratio. Intimal hyperplasia, expressed as the ratio of neointimal area to total wall area (A), is directly related to the injury, assessed by the ratio of internal elastic lamina (IEL) fracture length to IEL circumference (B), r = 0.84, p = 0.002. Restenosis injury index, defined as A/B, provides a useful tool for the quantitative assessment of future angioplasty-related restenosis interventions.
American Heart Journal 01/1994; 126(6):1334-40. · 4.65 Impact Factor
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ABSTRACT: A 53-year-old woman presented with increasing dyspnea over one month and signs of severe heart failure. A right ventricular biopsy revealed giant cell myocarditis. She was treated with a combination of cyclosporine, imuran and prednisone and improved dramatically--left ventricular ejection fraction increased from 13 to 66%. That such a response is possible has important implications with respect to both the etiology and treatment of this rare disorder.
The Canadian journal of cardiology 11/1992; 8(8):788-92. · 3.36 Impact Factor
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ABSTRACT: Parallel wire stents were implanted over exchange guide wires at percutaneous transluminal coronary angioplasty sites in 27 canine coronary arteries that were predilated with slightly oversized balloons. Stents were stainless steel, self-expandable, 3.5 to 4.5 mm in diameter, 9 to 12 mm in length, and were made of 10 wires that were longitudinally laser-welded in a zig-zag design. The compressible stent was delivered by the withdrawal of a Teflon outer catheter (4.2 to 4.9F) and the push of a polyethylene inner catheter. Aspirin, 80 mg per day, was given from the day before the study began, and heparin (150 U/kg) was administered during implantation. Quantitative angiography and pathologic examinations were performed at day 0 and at weeks 2, 4, 12, 26 and 52. The coronary angiographic diameter at the stent site immediately after stenting marginally increased from diameter before stenting: 3.22 +/- 0.40 mm versus 3.14 +/- 0.37 mm (p = 0.03), and during a mean of 14 weeks of follow-up, remained unaltered from immediate post-stenting: 3.29 +/- 0.43 mm versus 3.22 +/- 0.40 mm (p = NS) with no stent displacement. Comparisons of patency and thrombosis between heparin-coated and uncoated stents, between left anterior descending and circumflex arteries, and among the three different diameters of stents showed uniformly good results. At microscopy, the wires were oriented perfectly and embedded in the arterial wall, and by 2 weeks they were covered by mucopolysaccharide ground substance, smooth muscle cells, and an almost complete monolayer of neoendothelial cells.(ABSTRACT TRUNCATED AT 250 WORDS)
American Heart Journal 06/1991; 121(5):1522-30. · 4.65 Impact Factor
