[Show abstract][Hide abstract] ABSTRACT: MRI in patients with LV leads may cause tissue or lead heating, dislodgement, venous damage, or lead dysfunction.Objective
Determine the safety of MRI in patients with LV pacing leads.Methods
Prospective data were collected in patients with CS LV leads undergoing clinically indicated MRI at 3 institutions. Patients were not pacemaker dependent. Scans were performed under pacing nurse, technician, radiologist, and physicist supervision using continuous vital sign, pulse oximetry, and ECG monitoring and a 1.5 T scanner with SAR < 1.5 Watts/kg. Devices were interrogated pre- and post-MRI, programmed to asynchronous or inhibition mode with tachyarrhythmia therapies off (if present) and reprogrammed to their original settings post-MRI.ResultsMRI scans (n=42) were performed in 40 patients with non-MRI conditional LV leads between 2005-2013 (mean age 67 ± 9 years, n=16 or 40% women, median lead implant duration 740 days with IQ range 125-1173 days). MRIs were performed on the: head/neck/spine (n=35, 83%), lower extremities (n=4, 10%), chest (n=2, 5%), and abdomen (n=1, 2%). There were no overall differences in pre- and post-MRI interrogation LV lead sensing (12.4 ± 6.2 vs. 12.9 ± 6.7 mV, p=0.38), impedance (724 ± 294 vs. 718 ± 312 Ohms, p=0.67), or threshold (1.4 ± 1.1 vs. 1.4 ± 1.0 V, p=0.91). There were no individual LV lead changes requiring intervention.ConclusionMRI scanning was performed safely in non-pacemaker dependent patients with CS LV leads who were carefully monitored during imaging without clinically significant adverse effect on LV lead function.
[Show abstract][Hide abstract] ABSTRACT: Background
Cardiac resynchronization therapy (CRT) has been shown to improve heart failure (HF) symptoms and survival. We hypothesized that a greater improvement in left-ventricular ejection fraction (LVEF) after CRT is associated with greater survival benefit.
Methods & results
In 693 patients across two international centers, the improvement in LVEF post-CRT was determined. Patients were grouped as non/modest-, moderate-, or super-responders to CRT, defined as an absolute change in LVEF of ≤5%, 6-15% and >15%, respectively. Changes in NYHA class and LVEDD were assessed for each group.
There were 395 non/modest-, 186 moderate- and 112 super-responders. Super-responders were more likely to be female, have DCM, have lower creatinine, and have lower pulmonary artery systolic pressure (PASP) than non/modest- or moderate-responders. Super-responders were also more likely to have lower LVEF than non/modest-responders. There was no difference in NYHA class, MR-grade, and TR-grade between groups. Improvement in NYHA class (-0.9±0.9 vs. -0.4±0.8 [P<0.001] and -0.6±0.8 [P=0.02]) and LVEDD (-8.7±9.9mm vs. -0.5±5.0 and -2.4±5.8, [P<0.001 for both]) was greatest in super-responders. Kaplan-Meier survival analysis revealed super-responders achieved better survival compared to non/modest- (P<0.001) and moderate-responders (P=0.049).
Improvement in HF symptoms and survival after CRT is proportionate to the degree of improvement in LV systolic function. Super response is more likely in women, those with non-ischemic substrate, and those with lower pulmonary artery systolic pressure.
Journal of cardiac failure 06/2014; · 3.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: IntroductionAbandoned cardiovascular implantable electronic device (CIED) leads remain a contraindication to magnetic resonance imaging (MRI) studies, largely due to in vitro data showing endocardial heating secondary to the radiofrequency field. We tested the hypothesis that abandoned CIED leads do not pose an increased risk of clinical harm for patients undergoing MRI.Methods
This single-center retrospective study examined the outcomes of patients who had device generators removed before MRI, rendering the device leads abandoned. Information was gathered through chart review. Data collected included lead model, pacing threshold before MRI, anatomic region examined, threshold data after generator reimplantation, and clinical patient outcome.ResultsPatients (n = 19, 11 men and eight women) ranged in age from 19 to 85 at the time of MRI. There was a mean of 1.63 abandoned leads at the time of imaging; none of the leads were MRI conditional. Of the three implantable cardioverter defibrillator (ICD) leads, two of three were dual coil. Most (31/35) of the scans performed were of the central nervous system, including head and spinal imaging. There were no adverse events associated with MRI in any of these patients with abandoned leads within 7 days of the scan. No lead malfunctions or clinically significant change in pacing thresholds were noted with generator reimplantation.Conclusion
The use of MRI in patients with abandoned cardiac device leads appears feasible when performed under careful monitoring, with no adverse events, although the experience is small. MRI did not affect the function of leads that were subsequently reconnected to a cardiac device.
Pacing and Clinical Electrophysiology 05/2014; · 1.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: -Constrictive pericarditis is a potentially reversible cause of heart failure that may be difficult to differentiate from restrictive myocardial disease and severe tricuspid regurgitation. Echocardiography provides an important opportunity to evaluate for constrictive pericarditis, and definite diagnostic criteria are needed.
-Patients with surgically-confirmed constrictive pericarditis (n=130) at Mayo Clinic (2008-2010) were compared to patients (n=36) diagnosed with restrictive myocardial disease or severe tricuspid regurgitation after constrictive pericarditis was considered but ruled out. Comprehensive echocardiograms were reviewed in blinded fashion. Five principal echocardiographic variables were selected based on prior studies and potential for clinical use: 1) respiration-related ventricular septal shift; 2) variation in mitral inflow E velocity; 3) medial mitral annular e' velocity; 4) ratio of medial mitral annular e' to lateral e'; and 5) hepatic vein expiratory diastolic reversal ratio. All five principal variables differed significantly between the groups. In patients with atrial fibrillation or flutter (n=29), all but mitral inflow velocity remained significantly different. Three variables were independently associated with constrictive pericarditis: 1) ventricular septal shift, 2) medial mitral e'; and 3) hepatic vein expiratory diastolic reversal ratio. The presence of ventricular septal shift in combination with either medial e' ≥ 9 cm/s or hepatic vein expiratory diastolic reversal ratio ≥ 0.79 corresponded to a desirable combination of sensitivity (87%) and specificity (91%). The specificity increased to 97% when all three factors were present but the sensitivity decreased to 64%.
-Echocardiography may allow differentiation of constrictive pericarditis from heart failure due to restrictive myocardial disease or severe tricuspid regurgitation. Respiration-related ventricular septal shift, preserved or increased medial mitral annular e' velocity, and prominent hepatic vein expiratory diastolic flow reversals are independently associated with the diagnosis of constrictive pericarditis.
[Show abstract][Hide abstract] ABSTRACT: To determine whether surgical pericardiectomy is a safe and effective alternative to medical management for chronic relapsing pericarditis.
Retrospective review of 184 patients presenting to the Mayo Clinic in Rochester, Minnesota, from January 1, 1994, through December 31, 2005, with persistent relapsing pericarditis identified 58 patients who had a pericardiectomy after failed medical management and 126 patients who continued with medical treatment only. The primary outcome variables were in-hospital postoperative mortality or major morbidity, all-cause death, time to relapse, and medication use.
Mean ± SD follow-up was 5.5±3.5 years in the surgical group and 5.4±4.4 years in the medical treatment group. At baseline, patients in the surgical group had higher mean relapses (6.9 vs 5.5; P=.01), were more likely to be taking colchicine (43.1% [n=25] vs 18.3% [n=23]; P=.002) and corticosteroids (70.7% [n=41] vs 42.1% [n=53]; P<.001), and were more likely to have undergone a prior pericardiotomy (27.6% [n=16] vs 11.1% [n=14]; P=.003) than the medical treatment group. Perioperative mortality (0%) and major morbidity (3%; n=2) were minimal. Kaplan-Meier analysis revealed no differences in all-cause death at follow-up (P=.26); however, the surgical group had a markedly decreased relapse rate compared with the medical treatment group (P=.009). Medication use was notably reduced after pericardiectomy.
In patients with chronic relapsing pericarditis in whom medical management has failed, surgical pericardiectomy is a safe and effective method of relieving symptoms.
Mayo Clinic Proceedings 11/2012; 87(11):1062-70. · 5.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: This study aimed to evaluate the predictive value of a baseline speckle tracking strain rate imaging-derived discoordination index for response to cardiac resynchronization therapy (CRT).
Ninety-seven patients with QRS ≥120 ms and left ventricular (LV) ejection fraction ≤35% were prospectively followed after CRT in the Mayo CRT Registry. The LV discoordination index (stretch/shortening or thinning/thickening during ejection) was calculated from three types of deformation, radial, circumferential, and longitudinal, using two-dimensional speckle tracking strain rate imaging. The benefit of CRT was evaluated by reverse remodelling (i.e. reduction of LV end-systolic volume ≥15% at 6-month follow-up) and survival. The optimal cut-off value of the baseline discoordination index in discriminating responders from non-responders was determined by receiver operating characteristic curve analysis. Significant differences in baseline indices between responders and non-responders were noted for radial and circumferential discoordination indices. A mid-ventricular radial discoordination index (RDI-M) >38% best predicted responders, especially in patients with ischaemic cardiomyopathy (area under the curve 0.86 for all patients, sensitivity 80%, and specificity 91%). Death occurred in 28 patients over a median follow-up of 3.2 years. When adjusted for confounding variables, lack of significant discoordination (RDI-M <38%) before CRT was associated with a particularly high mortality (hazard ratio 7.05, 95% confidence interval 2.45-26.0).
LV discoordination assessed by speckle tracking RDI-M imaging was able to predict reverse remodelling at 6 months and survival of patients who received CRT.
European Journal of Heart Failure 03/2012; 14(5):517-25. · 6.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The goal of this study was to determine the impact of transvenous pacemaker and defibrillator leads on the incidence of bioprosthetic tricuspid valve (BTV) regurgitation compared with BTV patients without a transvalvular lead.
Although concern has been raised regarding the potential deleterious effect of permanent transvenous device leads on BTV function, little is known about the incidence of prosthetic tricuspid regurgitation (TR) after lead placement.
A retrospective review of 58 patients who underwent BTV implantation and subsequently required endocardial pacemaker (n = 52) or defibrillator (n = 6) lead implantation across the BTV was conducted. Patient and prosthesis characteristics, lead type, and clinical events were collected. The incidence and severity of prosthetic TR, determined by Doppler echocardiography, was compared with 265 consecutive patients who underwent BTV implantation without undergoing subsequent transvalvular device lead implantation.
Over a mean follow-up of 25 months, in 5 patients (9%) with a transvalvular lead significant (moderate or greater) prosthetic TR developed compared with 12 patients (5%) in the control group (p = 0.20). Kaplan-Meier analysis revealed no significant difference in the incidence of TR in BTV patients with and without transvalvular leads (p = 0.45). Significant prosthetic TR in patients with and without a transvalvular lead more commonly occurred 2 years or later after lead or BTV implantation (4 of 5, 80% and 10 of 12, 83%, respectively).
Transvalvular device lead implantation in BTV patients was not associated with an increased incidence of significant prosthetic TR (p = 0.45). Based on these data, transvalvular lead implantation appears to be an acceptable approach for patients with a BTV who require permanent pacemaker or defibrillator placement.
Journal of the American College of Cardiology 02/2012; 59(9):813-8. · 15.34 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Constrictive pericarditis (CP) is a disabling disease, and usually requires pericardiectomy to relieve heart failure. Reversible CP has been described, but there is no known method to predict the reversibility. Pericardial inflammation may be a marker for reversibility. As a pilot study, we assessed whether cardiac magnetic resonance imaging pericardial late gadolinium enhancement (LGE) and inflammatory biomarkers could predict the reversibility of CP after antiinflammatory therapy.
Twenty-nine CP patients received antiinflammatory medications after cardiac magnetic resonance imaging. Fourteen patients had resolution of CP, whereas 15 patients had persistent CP after 13 months of follow-up. Baseline LGE pericardial thickness was greater in the group with reversible CP than in the persistent CP group (4 ± 1 versus 2 ± 1 mm, P = 0.001). Qualitative intensity of pericardial LGE was moderate or severe in 93% of the group with reversible CP and in 33% of the persistent CP group (P = 0.002). Cardiac magnetic resonance imaging LGE pericardial thickness ≥ 3 mm had 86% sensitivity and 80% specificity to predict CP reversibility. The group with reversible CP also had higher baseline C-reactive protein and erythrocyte sedimentation rate than the persistent CP group (59 ± 52 versus 12 ± 14 mg/L, P = 0.04 and 49 ± 25 versus 15 ± 16 mm/h, P = 0.04, respectively). Antiinflammatory therapy was associated with a reduction in C-reactive protein, erythrocyte sedimentation rate, and pericardial LGE in the group with reversible CP but not in the persistent CP group.
Reversible CP was associated with pericardial and systemic inflammation. Antiinflammatory therapy was associated with a reduction in pericardial and systemic inflammation and LGE pericardial thickness, with resolution of CP physiology and symptoms. Further studies in a larger number of patients are needed.
[Show abstract][Hide abstract] ABSTRACT: Previous studies have demonstrated that mitral annulus early diastolic (e') velocity is increased in constrictive pericarditis (CP) and reduced in restrictive cardiomyopathy. However, those studies did not comprehensively evaluate mitral and tricuspid annular velocities before and after pericardiectomy.
We performed comprehensive echocardiography before and after pericardiectomy in 99 patients with CP, 52 with primary (idiopathic or postpericarditis etiology) and 47 with secondary CP (due to surgery or radiation). Overall, mean ± SD mitral medial, mitral lateral, and tricuspid lateral e' velocities were 12.2 ± 4.2, 10.0 ± 5.4, and 11.6 ± 3.5 cm/s, respectively; annular late diastolic velocities were 10.3 ± 4.3, 12.2 ± 4.9, and 11.7 ± 5.4 cm/s, respectively; and annular systolic (s') velocities were 7.8 ± 2.8, 8.2 ± 2.1, and 11.2 ± 3.8 cm/s, respectively. Medial e' was equal to or greater than mitral lateral e' in 74% of analyzable cases. With the exception of tricuspid s', there were significant differences in all s' and e'velocities between primary and secondary CP before pericardiectomy. After pericardiectomy, all annular velocities decreased significantly (P < 0.02 for all comparisons). The reduction in medial e' velocity was greater than that of mitral lateral e' velocity (P < 0.0001 and P = 0.0004, respectively), and the mitral lateral/medial e' ratio normalized (P = 0.0002).
The mitral lateral/medial e' ratio is reversed in three fourths of patients with CP. All annular velocities are lower in secondary compared to primary CP before pericardiectomy. After pericardiectomy, there is reduction of all annular velocities and normalization of the mitral lateral/medial e' ratio.
[Show abstract][Hide abstract] ABSTRACT: The purpose of this study was to determine if anodal stimulation accounts for failure to benefit from cardiac resynchronization therapy (CRT) in some patients.
Approximately 30-40% of patients with moderate to severe heart failure do not have symptomatic nor echocardiographic improvement in cardiac function following CRT. Modern CRT devices allow the option of programming left ventricular (LV) lead pacing as LV tip to right ventricular (RV) lead coil to potentially improve pacing thresholds. However, anodal stimulation can result in unintentional RV pacing (anode) instead of LV pacing (cathode).
Patients enrolled in our center's CRT registry had an echocardiogram, 6-minute walk (6MW), and Minnesota Living with HF Questionnaire (MLHFQ) pre-implant and 6 months after CRT. Electrocardiograms (12 lead) during RV, LV, and biventricular (BiV) pacing were obtained at the end of the implant in 102 patients. Anodal stimulation was defined as LV pacing QRS morphology on EKG being identical to RV pacing or consistent with fusion with RV and LV electrode capture. LV end systolic volume (LVESV) was measured by echo biplane Simpson's method and CRT responder was defined as 15% or greater reduction in LVESV.
Of the 102 patients, 46 (45.1%) had the final LV lead pacing configuration programmed LV (tip or ring) to RV (coil or ring). 3 of the 46 subjects (6.5%) had EKG findings consistent with anodal stimulation, not corrected intraoperatively. All anodal stimulation patients were nonresponders to CRT by echo criteria (reduction in LVESV 13.3 ± 0.6%, increase in EF 5.0 ± 1.4%) compared to 46% responders for those without anodal stimulation, (change in LVESV 18.7 ± 25.6%, EF 7.6 ±10.9%). None of the anodal stimulation patients were responders for the 6 minute walk, compared to 32 of 66 (48%) of those without anodal stimulation.
Anodal stimulation is a potential underrecognized and ameliorable cause of poor response to CRT.
Indian pacing and electrophysiology journal 05/2011; 11(3):64-72.
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[Show abstract][Hide abstract] ABSTRACT: Whether mechanical dyssynchrony indices predict reverse remodeling (RR) or clinical response to cardiac resynchronization therapy (CRT) remains controversial. This prospective study evaluated whether echocardiographic dyssynchrony indices predict RR or clinical response after CRT.
Of 184 patients with heart failure with anticipated CRT who were prospectively enrolled, 131 with wide QRS and left ventricular ejection fraction <35% had 6-month follow-up after CRT implantation. Fourteen dyssynchrony indices (feasibility) by M-mode (94%), tissue velocity (96%), tissue Doppler strain (92%), 2D speckle strain (65% to 86%), 3D echocardiography (79%), and timing intervals (98%) were evaluated. RR (end-systolic volume reduction ≥15%) occurred in 55% and more frequently in patients without (71%) than in patients with (42%) ischemic cardiomyopathy (P=0.002). Overall, only M-mode, tissue Doppler strain, and total isovolumic time had a receiver operating characteristic area under the curve (AUC) greater than the line of no information, but none of these were strongly predictive of RR (AUC, 0.63 to 0.71). In nonischemic cardiomyopathy, no dyssynchrony index predicted RR. In ischemic cardiomyopathy, M-mode (AUC, 0.67), tissue Doppler strain (AUC, 0.79), and isovolumic time (AUC, 0.76) -derived indices predicted RR (P<0.05 for all), although the incremental value was modest. No indices predicted clinical response assessed by Minnesota Living with Heart Failure Questionnaire, 6-minute walk distance, and peak oxygen consumption.
These findings are consistent with the Predictors of Response to CRT study and do not support use of these dyssynchrony indices to guide use of CRT.
[Show abstract][Hide abstract] ABSTRACT: Pericardial diseases can present clinically as acute pericarditis, pericardial effusion, cardiac tamponade, and constrictive pericarditis. Patients can subsequently develop chronic or recurrent pericarditis. Structural abnormalities including congenitally absent pericardium and pericardial cysts are usually asymptomatic and are uncommon. Clinicians are often faced with several diagnostic and management questions relating to the various pericardial syndromes: What are the diagnostic criteria for the vast array of pericardial diseases? Which diagnostic tools should be used? Who requires hospitalization and who can be treated as an outpatient? Which medical management strategies have the best evidence base? When should corticosteroids be used? When should surgical pericardiectomy be considered? To identify relevant literature, we searched PubMed and MEDLINE using the keywords diagnosis, treatment, management, acute pericarditis, relapsing or recurrent pericarditis, pericardial effusion, cardiac tamponade, constrictive pericarditis, and restrictive cardiomyopathy. Studies were selected on the basis of clinical relevance and the impact on clinical practice. This review represents the currently available evidence and the experiences from the pericardial clinic at our institution to help guide the clinician in answering difficult diagnostic and management questions on pericardial diseases.
Mayo Clinic Proceedings 06/2010; 85(6):572-93. · 5.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Right ventricular pacing increases the risk of heart failure in adults with structural heart disease. The impact of prolonged right ventricular pacing in adults without structural heart disease is not fully characterized and may depend on interactions of pacing with abnormal substrate predisposing to ventricular dysfunction.
We assessed the effect of right ventricular pacing in patients who underwent pacemaker implantation for isolated congenital atrioventricular block between 1964 and 2005. To assess for immunologic contribution to cardiac dysfunction, outcomes were compared between patients with (Ab(+)) and without (Ab(-)) antinuclear antibody during adulthood and an age- and sex-matched Olmsted County, Minnesota, population. Of 103 patients (mean+/-SD age, 32+/-19 years), 18 were Ab(+). Long-term survival free of new heart failure after pacemaker implantation in isolated congenital atrioventricular block patients was worse than in the matched population (P<0.001). This difference was attributable to the development of heart failure in 12 Ab(+) patients (67%; P<0.001), without differences between Ab(-) patients (2%) and the matched population (2%; P=0.7). Compared with baseline, at last follow-up, left ventricular ejection fraction did not decline in Ab(-) (53+/-9% to 57+/-12%) but decreased in Ab(+)(52+/-10% to 38+/-12%; P=0.03) patients. Survival was similar in Ab(-) patients and the Minnesota population (98%; P=0.7) but worse in Ab(+) patients (79%; P<0.01).
The natural history of patients with isolated congenital atrioventricular block who require pacing depends upon their antibody status. Antinuclear antibody status was a predictor for the development of heart failure and death. Long-term right ventricular pacing alone does not appear to be associated with development of heart failure, deterioration in ventricular function, or reduced survival in Ab(-) isolated congenital atrioventricular block patients.