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Objective There has been concern about persisting cardiac effects of electroconvulsive therapy (ECT). Several studies have analyzed Holter monitor recordings before and after ECT, and generally have found no significant effects. Methods As part of a study on heart rate variability changes in ECT, we performed 2-3 hour Holter monitoring before and at least 1 hour after courses of ECT in 11 depressed patients without cardiac illness. Results There was no significant difference before and after Ect in heart rate, frequency ofventricular or supraventricular events, or in ST segments. Conclusion These date provide further evidnece of the general cardiac safety of ECT.

Objective To describe heart rate variability (HRV) analysis, especially time- and frequencydomain analyses, and some of its investigational applications in clinical cardiovascular medicine. Design We provide a brief introduction to the magnitude of sudden cardiac death and the factors that influence life-threatening ventricular arrhythmias as a backdrop to the potential importance of the autonomic nervous system and how this system might be assessed by the analysis of HRV. Material and Methods We reviewed the literature from 1973 to 1994 that described beat-to-beat changes in heart rate, heart rate signal recording and processing, and investigational applications of HRV analysis to cardiovascular medicine. Results Beat-to-beat changes in heart rate are partly influenced by the autonomic nervous system. Briefly, changes in sympathetic input to the sinoatrial node affect low-frequency HRV, whereas changes in parasympathetic input affect high-frequency HRV. Multiple physiologic and non physiologic determinants of HRV exist, and therefore analysis of HRV as a direct "window" to autonomic tone is problematic. Conclusion In selected patient populations, analysis of HRV yields important information about sinoatrial responsiveness to autonomic input and mortality risk stratification. Routine application of HRV analysis to clinical cardiovascular medicine awaits further investigation, however.

Objective To extend the application of signal-averaged electrocardiography (SAECG) to patients with ventricular conduction defects by analysis of electrocardiographic (ECG) time-domain variables. Material and Methods In 123 consecutive patients with a QRS duration of 118 ms or more on a resting ECG and without evidence of an accessory pathway, SAECG was done at the time of electrophysiologic (EP) study. For EP testing, up to three stimuli were delivered during two paced drives from two right ventricular sites. A "positive" EP result was defined as monomorphic ventricular tachycardia that lasted for more than 30 seconds or necessitated intervention. Data were obtained for four time-domain variables. All variables were analyzed for differences between patients with EP-positive and those with EP-negative results. Results Unfiltered QRS duration was the only time-domain ECG variable that was statistically different ( P = 0.02) between patients with EP-positive and those with EP-negative results (141.3 and 147.8 ms, respectively); this difference persisted when patients with right bundle branch block were excluded from analysis. This finding is the opposite of previously reported observations. When only patients with ischemic heart disease were analyzed, no SAECG variables were significantly different between patients with inducible ventricular tachycardia and those without it. Conclusion High-resolution ECG time-domain variables cannot be used to predict inducibility of ventricular tachycardia during EP testing in patients with conduction defects.

This multicenter study reports the outcome of ventricular tachycardia (VT) therapy (conversion or acceleration) and the relationship to initial tachycardia cycle length and other clinical variables using an implantable device with the capability of autodecremental or burst pacing, cardioversion, and defibrillation. The device was implanted in 444 patients (mean age 58 +/- 15 years) with 1,240 episodes of VT induced with noninvasive programming and reported in a multicenter database. Only the first sequence attempted for conversion by pacing or cardioversion was assessed, and cardioversion energies were 0.2-5 J. Autodecremental pacing was used to treat 700 induced episodes of VT during titration of pacing therapies (57% converted and 12% accelerated), burst pacing to treat 357 episodes (49% converted under 11% accelerated), and cardioversion to treat 183 episodes (82% converted and 4% accelerated). Cardioversion was the most effective treatment and had the lowest acceleration rate. Shorter VT cycle lengths were more likely to accelerate with burst pacing and longer VT cycle lengths to convert with both burst and autodecremental pacing. Patients with higher ejection fractions were more likely to convert with autodecremental and burst pacing. Use of cardioversion, higher ejection fraction, absence of unrepaired aneurysm, longer VT cycle lengths, coronary artery disease, and use of autodecremental pacing predicted conversion. Lower ejection fraction and VT cycle lengths < or = 300 msec predicted tachycardia acceleration.

Background— Implantable cardioverter-defibrillators (ICDs) are increasingly used for primary prevention after randomized, controlled trials demonstrating that they reduce the risk of death in patients with left ventricular systolic dysfunction. The extent to which the clinical characteristics and long-term outcomes of unselected, community-based patients with left ventricular systolic dysfunction undergoing primary prevention ICD implantation in a real-world setting compare with those enrolled in the randomized, controlled trials is not well characterized. This study is being conducted to address these questions. Methods and Results— The study cohort includes consecutive patients undergoing primary prevention ICD placement between January 1, 2006 and December 31, 2009 in 7 health plans. Baseline clinical characteristics were acquired from the National Cardiovascular Data Registry ICD Registry. Longitudinal data collection is underway, and will include hospitalization, mortality, and resource use from standardized health plan data archives. Data regarding ICD therapies will be obtained through chart abstraction and adjudicated by a panel of experts in device therapy. Compared with the populations of primary prevention ICD therapy randomized, controlled trials, the cohort (n=2621) is on average significantly older (by 2.5–6.5 years), more often female, more often from racial and ethnic minority groups, and has a higher burden of coexisting conditions. The cohort is similar, however, to a national population undergoing primary prevention ICD placement. Conclusions— Patients undergoing primary prevention ICD implantation in this study differ from those enrolled in the randomized, controlled trials that established the efficacy of ICDs. Understanding a broad range of health outcomes, including ICD therapies, will provide patients, clinicians, and policy makers with contemporary data to inform decision-making.

Anatomy of the Coronary Venous System. Introduction: Cannulation of the coronary sinus (CS) is a prerequisite for left ventricular (LV) pacing and certain ablation procedures. The detailed regional anatomy for the coronary veins and potential anatomic causes for difficulty with these procedures has not been established. Methods and Results: Therefore, we performed macroscopic measurements in 620 autopsied hearts (mean age 60 ± 23 years, 44% female). The CS was preserved for analysis in 96%. Sixty-three percent had a Thebesian valve that covered the posterior aspect of the CS ostium with extension to the superior (50%) and inferior aspects (18%) and was obstructive with fenestrations in 3 specimens. Partial or near occlusive valves were present occasionally at the ostium of the great cardiac vein (Vieussens; 8%) and middle cardiac vein (5%). Ninety-three percent had left atrial branches, and 41% had at least one branch with lumen > 3 French. For CRT lead placement, the mid-lateral LV was accessible from the middle cardiac vein (20%), the left posterior vein (92%) or the anterior interventricular vein (86%). Among specimens where the left phrenic nerve was preserved it crossed the LV mid-lateral wall in 45%. Conclusions: Epicardial coronary vein anatomy is variable, and the mid-lateral LV wall can potentially be accessed through various tributaries of the epicardial veins. The orientation of the Thebesian valve favors cannulation of the CS from an anterior (ventricular) and inferior approach. Anterobasal, mid-lateral, and inferior apical LV coronary veins lie in proximity to the course of the phrenic nerve. (J Cardiovasc Electrophysiol, Vol. 24, pp. 1-6, January 2013)

Aldosterone antagonist therapy is recommended for selected patients with heart failure and reduced ejection fraction. Adherence to therapy in the transition from hospital to home is not well understood.We identified patients with heart failure and reduced ejection fraction who were ≥65 years old, eligible for aldosterone antagonist therapy, and discharged home from hospitals in the Get With the Guidelines-Heart Failure registry between January 1, 2005, and December 31, 2008. We used Medicare prescription drug event data to measure adherence. Main outcome measures were prescription at discharge, outpatient prescription claim within 90 days, discontinuation, and adherence as measured with the medication possession ratio. We used the cumulative incidence function to estimate rates of initiation and discontinuation.Among 2,086 eligible patients, 561 (26.9%) were prescribed an aldosterone antagonist at discharge. Within 90 days, 78.6% of eligible patients with a discharge prescription filled a prescription for the therapy, compared with 13.0% of eligible patients without a discharge prescription (P.001). The median medication possession ratio was 0.63 over 1 year of follow-up. Among 634 patients who filled a prescription within 90 days of discharge, 7.9% discontinued therapy within 1 year.Most eligible patients were not prescribed aldosterone antagonist therapy at discharge from a heart failure hospitalization. Eligible patients without a discharge prescription seldom initiated therapy as outpatients. Most patients who were prescribed an aldosterone antagonist at discharge filled the prescription within 90 days and remained on therapy.

Background— Prior studies have demonstrated low use of implantable cardioverter defibrillators (ICDs) as primary prevention, particularly among women and blacks. The degree to which the overall use of ICD therapy and disparities in use have changed is unclear. Methods and Results— We examined 11 880 unique patients with a history of heart failure and left ventricular ejection fraction ≤35% who were ≥65 years old and enrolled in the Get With the Guidelines–Heart Failure (GWTG-HF) program from January 2005 through December 2009. We determined the rate of ICD use by year for the overall population and for sex and race groups. From 2005 to 2007, overall ICD use increased from 30.2% to 42.4% and then remained unchanged in 2008 to 2009. After adjustment for potential confounders, ICD use increased significantly in the overall study population during 2005 to 2007 (odds ratio, 1.28; 95% confidence interval, 1.11–1.48 per year; P =0.0008) and in black women (odds ratio, 1.82; 95% confidence interval, 1.28–2.58 per year; P =0.0008), white women (odds ratio, 1.30; 95% confidence interval, 1.06–1.59 per year; P =0.010), black men (odds ratio, 1.54; 95% confidence interval, 1.19–1.99 per year; P =0.0009), and white men (odds ratio, 1.25; 95% confidence interval, 1.06–1.48 per year; P =0.0072). The increase in ICD use was greatest among blacks. Conclusions— In the GWTG-HF quality improvement program, a significant increase in ICD therapy use was observed over time in all sex and race groups. The previously described racial disparities in ICD use were no longer present by the end of the study period; however, sex differences persisted.

Objectives. This study was designed to evaluate the presence or absence of atypical T wave evolution in patients with a postinfarclion pericardial effusion but without clinically recognized postinfarction pericarditis. A second purpose was to evaluate the frequency of atypical T wave evolution in a previous study of postinfarction pericarditis. Background. Electrocardiographic (ECG) criteria involving the evolution of the T wave after an acute myocardial infarction were recently described in patients with regional postinfarction pericarditis. Atypical T wave evolution was found to have a sensitivity of 100% and a specificity of 77% for clinically recognized regional postinfarction pericarditis with or without a pericardial effusion. Methods. The hospital records and serial ECGs of 20 patients with clinically recognized postinfarction pericarditis (Group I) were reviewed. The records and serial ECGs of 20 additional patients with a postinfarction pericardial effusion without clinically recognized postinfarction pericarditis (Group II) were also examined. The type of postinfarction T wave pattern, typical or atypical, was recorded in both groups. Results. All 20 patients in Group I had atypical T wave evolution. Among the 20 patients in Group II, every patient also had atypical T wave evolution. Fifteen percent of all 40 patients with atypical T wave evolution had a non-Q wave infarction with definite or inferred postinfarction pericarditis. Conclusions. The high sensitivity of atypical T wave evolution in diagnosing regional postinfarction pericarditis was confirmed. However, similar T wave alterations were also observed when a postinfarction pericardial effusion existed in the absence of clinically recognized pericarditis. Fifteen percent of patients with atypical T wave evolution had a non-Q wave infarction with definite or inferred pericardial involvement. Thus, the presence of atypical T wave evolution may be a more sensitive indicator of a transmural infarction than the development of a Q wave.

Permanent pacing can prevent recurrent symptoms and reduce mortality in elderly patients with symptomatic high-degree atrioventricular (AV) block. However, long-term survival with respect to comparable control subjects has not been well defined. In our study, relative long-term survival and prognostic predictors after permanent pacemaker implantation for symptomatic high-degree AV block were assessed among all residents of Olmsted County, Minnesota, who were > or = 65 years old. Of the 154 patients, 77 were men and 77 were women (mean age 80 +/- 7 years). Follow-up was 0.1 to 19.8 years (mean 4.2 +/- 2.8). Sixty-nine patients had isolated AV block and 85 had coexisting heart disease. Observed survival at 1, 3, 5, and 10 years was 85%, 68%, 52%, 21%, and 72%, 50%, 31%, 11% for patients with isolated AV block and patients with coexisting heart disease, respectively (p = 0.006). Observed survival in patients 65 to 79 years old with isolated AV block was comparable to age- and sex-matched cohorts (p = 0.53), but in patients aged > or = 80 years, it was less than that for control subjects (p = 0.014). In patients with coexisting heart disease, observed survival was less than that for control subjects in patients 65 to 79 years old (p or = 80 years (p < 0.001). Multivariate analysis identified congestive heart failure, chronic obstructive pulmonary disease, age, syncope, insulin-dependent diabetes mellitus, and male gender as independent predictors of increased mortality.

Objective To describe the use of a new implantable cardioverter defibrillator (ICD) that can be placed in the prepectoral region rather than implanted in the abdominal wall. Design We report the experience of placement of this new ICD in the prepectoral region in 13 patients from Sept. 28, 1993, through Jan. 10, 1994, at the Mayo Clinic. Material and Methods Thirteen consecutive patients offered this new ICD underwent placement of transvenous defibrillation leads, and the pulse generator was placed in a pocket formed in the subcutaneous, prepectoral space. Testing ensured a defibrillation threshold of 24 J or less. Results In all 13 patients, the pulse generator could be placed in the subcutaneous, prepectoral space. In all except one patient, acceptable defibrillation thresholds were achieved by using lead systems placed totally transvenously. Only one patient required placement of a subcutaneous patch. All but two patients were dismissed from the hospital within 3 days after the ICD implantation. Conclusion Consistent subcutaneous, prepectoral placement of this new ICD pulse generator is possible. Because the entire procedure can be performed in the pacemaker implantation room, the potential exists for decreasing the duration of the hospitalization and associated costs.

There is only limited data on normal reference values for signal-averaged electrocardiograms (SAECGs) using Frank leads and fast Fourier transform filter (FFT). Furthermore, the influence of gender on reference values and their relation to body characteristics was only the subject of a few studies on small series of normals. One hundred eighty-five cardiac normals (85 women and 100 men) were examined in this multicenter study. The obtained SAECG values (mean +/- standard deviation) are as follows: filtered QRS duration (FQRSD) = 108.6 +/- 7.5 msec; low amplitude signal duration40 microV (LASD) = 30.4 +/- 8.4 msec; and root mean square voltage in the terminal 40 msec (RMSV) = 43.5 +/- 20.6 microV. Between men and women, significant differences were found in FQRSD (111.7 +/- 6.5 vs 105.0 +/- 7.0 msec, P0.001) and in RMSV (38.6 +/- 17.4 vs 49.4 +/- 22.7 microV, P0.001). No difference was observed for LASD. After normalizing the three SAECG parameters for body characteristics, FQRSD normalized for height was the only variable where gender differences were eliminated. For FQRSD and LASD the 90th percentile and for RMSV the 10th percentile are proposed as cut-off values. Only for the 90th percentile of FQRSD a clear difference between men and women was observed. The following gender specific normal values for SAECG, at 40-Hz high pass filtering, using Frank leads and an FFT filter are proposed: for males, FQRSD122 msec; for females, FQRSD115 msec; for both genders, LASD41 msec and RMSV20 microV.

Background/Aims Implantable cardioverter defibrillators (ICDs) result in striking mortality benefits among randomized trial populations, but elucidation of outcomes in real-world populations is needed to optimize care and coverage decisions. The Cardiovascular Research Network (CVRN) Longitudinal ICD Study is a new 7-site 3.5-year project evaluating the rate of appropriate device therapies, device complications, hospitalization, mortality, and utilization/cost among a cohort of primary prevention ICD patients.

Background— The efficacy of radiofrequency ablation for atrial fibrillation (AF) in patients with left ventricular (LV) systolic dysfunction and isolated diastolic dysfunction is uncertain. Methods and Results— A prospective cohort of patients with normal and abnormal LV function underwent ablation for antiarrhythmic drug (AAD)-refractory AF. Three groups were compared: 111 patients with systolic dysfunction, defined as LV ejection fraction (LVEF) ≤40%; 157 patients with isolated diastolic dysfunction but preserved LVEF ≥50%; and 100 patients with normal LV function. The primary end point was AAD-free AF elimination at 1 year after ablation. This end point was achieved in 62% of patients with systolic dysfunction, 75% of those with diastolic dysfunction, and 84% of controls ( P =0.007). AF control on or off AADs was achieved in 76% of patients with systolic dysfunction, 85% of those with diastolic dysfunction, and 89% of controls ( P =0.08). In the systolic dysfunction group, 49% experienced an increase in LVEF by ≥5% after ablation, of which 64% achieved normal LVEF. In the diastolic dysfunction group, 30% of patients demonstrated at least 1 grade improvement in diastolic dysfunction. Multivariable analysis demonstrated an increased relative risk of arrhythmia recurrence of 1.8 (95% CI, 1.1 to 3.1; P =0.02) in systolic dysfunction and 1.7 (1.0 to 2.7; P =0.04) in isolated diastolic dysfunction compared with normal function. Conclusions— Although an ablative approach for AF in patients with systolic or diastolic dysfunction is associated with an increased long-term recurrence risk, there is potential for substantial quality-of-life improvement and LV functional benefit.

PVCs and Left Ventricular Dysfunction. Background: Frequent premature ventricular complexes (PVCs) can cause a decline in left ventricular ejection fraction (LVEF). We investigated whether the site of origin and other PVC characteristics are associated with LVEF. Methods: We retrospectively studied 70 consecutive patients (mean age 42 ± 17 years, 40 [57%] female) with no other cause of cardiomyopathy undergoing ablation of PVCs. We analyzed the association of a reduced LVEF, defined by LVEF

Objectives. To test the hypothesis that certain clinical events may precede free wall myocardial rupture and allow its prediction, we conducted a retrospective and prospective study of 70 patients with rupture.Background. Rupture of the left ventricular free wall develops in approximately 10% of patients with fatal acute transmural myocardial infarction. Clinically, its occurrence has been considered precipitous and unexpected. Pathologically, however, rupture appears to be a stuttering, progressive process characterized in many instances by an infiltrating intramural hemorrhage and a thrombus within the tear of ≥1 day's duration.Methods. The clinical course and evolutionary electrocardiographic (ECG) changes in 70 consecutive patients with rupture and 100 comprison patients with acute myocardial infarction but without rupture were reviewed to ascertain whether certain clinical symptoms, signs and ECG alterations occur in patients prone to develop rupture, allowing its anticipation, In addition, a correlation was established between the site of infarction indicated by the ECG and the site of rupture determined at autopsy or surgery,Results. Patients with rupture had a significantly greater incidence of pericarditis, repetitive emesis and restlessness and agitation than did patients without rupture. More than 80% of patients with rupture had two or more symptoms compared with 3% of patients without rupture (p < 0.002). A deviation from the expected evolutionary T wave pattern occurred in 94% of patients with rupture and 34% of control patients (p ≤ 0.02), An abrupt transient episode of hypotension and bradycardia, probably due to the initial tearing of the epicardium with a resultant small hemopericardium, was observed in 21% of patients with rapture. Rupture of the midlateral wall was most common (32%) and usually occurred in the setting of an inferoposterolateral infarction related to an acute left circumflex artery occlusion. On the basis of these clinical and ECG changes, rupture was confirmed by echocardiography and pericardiocentesis in the two most recent ptients, and the defect was successfully repaired.Conclusions. Rupture is often preceded by particular symptoms, signs—namely, one or more episodes of abrupt, transient hypotension and bradycardia and unexpected alterations of the T waves, especially directional changes of the latter. Patients displaying these symptoms, signs and ECG changes require a bedside echocardiogram and echocardiographically guided pericardiocentesis if fluid is visualized. If the pericardiocentesis identifies the fluid as blood, immediate surgery is indicated.

BACKGROUND Virtually all natural history studies of Wolff-Parkinson-White (WPW) syndrome have been case series and, as such, have been constrained by referral biases, skewed age and sex distributions, or brief follow-up periods. The purpose of our study was to examine the natural history, the development of arrhythmias, and the incidence of sudden death in an entire cohort of pediatric and adult WPW patients from a community-based local population. METHODS AND RESULTS We identified 113 residents of Olmsted County, Minnesota, during the period 1953-1989 using the centralized records-linkage system provided by the Mayo Clinic and the Rochester Epidemiology Program Project. Medical records and ECGs were reviewed to confirm the diagnosis and to establish pathway location by ECG criteria. Follow-up, via record review and telephone interview, was complete in 95% of subjects through 1990. The incidence of newly diagnosed cases was approximately four per 100,000 per year. Preexcitation was not present on the initial ECG of 22% of the cohort. Approximately 50% of the population was asymptomatic at diagnosis, with 30% subsequently having symptoms related to arrhythmia at follow-up. Two sudden cardiac deaths (SCD) occurred over 1,338 patient-years of follow-up, yielding an overall SCD rate of 0.0015 (95% confidence interval, 0.0002-0.0054) per patient-year. No SCD occurred in patients asymptomatic at diagnosis. CONCLUSIONS The incidence of sudden death in a local community-based population is low and suggests that electrophysiological testing should not be performed routinely in asymptomatic patients with WPW syndrome. Nevertheless, young, asymptomatic patients, particularly those < 40 years old, should return for medical follow-up should symptoms develop.

Although several randomized clinical trials have demonstrated the safety and efficacy of catheter ablation of atrial fibrillation (AF) in experienced centers, the outcomes of this procedure in routine clinical practice and in patients with persistent and long-standing persistent AF remain uncertain. Brisk adoption of this therapy by physicians with diverse training and experience highlights potential concerns regarding the safety and effectiveness of this procedure. Some of these concerns could be addressed by a national registry of AF ablation procedures such as the Safety of Atrial Fibrillation Ablation Registry Initiative that was initially proposed at a Cardiac Safety Research Consortium Think Tank meeting in April 2009. In January 2010, the Cardiac Safety Research Consortium, in collaboration with the Duke Clinical Research Institute, the US Food and Drug Administration, the American College of Cardiology, and the Heart Rhythm Society, held a follow-up meeting of experts in the field to review the construct and progress to date. Other participants included the National Heart, Lung, and Blood Institute; the Centers for Medicare and Medicaid Services; the Agency for Healthcare Research and Quality; the AdvaMed AF working group; and additional industry representatives. This article summarizes the discussions that occurred at the meeting of the state of the Safety of Atrial Fibrillation Ablation Registry Initiative, the identification of a clear pathway for its implementation, and the exploration of solutions to potential issues in the execution of this registry.

Certain outflow tract tachyarrhythmias require ablation above the semilunar valves. Understanding of the regional anatomy of these arrhythmogenic sites is required to avoid complications.We examined 603 formalin-fixed autopsy hearts from October 1998 to July 2003. Three hundred forty-two of 603 (57%) had myocardial extensions above the aortic valve, and 446 of 602 (74%) had extensions above the pulmonary valve. Extensions were noted above the aortic right coronary cusp (RCC) in 332 of 603 (55%; 2.8 ± 1.2 mm), left coronary cusp (LCC) in 145 of 603 (24%; 1.5 ± 0.5 mm), and non-coronary/posterior cusp in four of 603 (0.66%; 1.3 ± 0.5 mm; p0.0001), intercuspally in 295 of 603 (49%; 2.2 ± 1.1 mm) and into the cusps in 13 of 603 (2.2%). Extensions were noted above the pulmonary right cusp in 360 of 602 (60%; 4.0 ± 2.5 mm), posterior/left cusp in 313 of 602 (52%; 3.6 ± 2.1 mm), and anterior cusp in 268 of 602 (45%; 3.7 ± 2.2 mm; p0.0001), intercuspally in 438 of 602 (73%; 3.4 ± 1.8 mm) and into the cusps in ten of 602 (1.7%). The left main coronary artery was closer to the myocardial extensions above the nearest pulmonary valve cusp (posterior) than those above the nearest aortic valve cusp (LCC; 4.8 ± 1.7 vs. 16.3 ± 3.3 mm, p = 0.0005).Myocardial extensions are common into the great arteries above the semilunar cusps and intercuspally, and rarely into the cusps themselves. The extensions are larger and more symmetric above the pulmonary cusps as compared to the aortic cusps, the most prominent aortic extensions being above the RCC. The left main coronary artery courses close to the extensions above the posterior pulmonary cusp.

Cardiac resynchronization therapy (CRT) is a therapy of proven benefit in patients with advanced heart failure. Identifying potential responders remains challenging, and whether the etiology of the heart failure is related to the potential hemodynamic benefit and long-term outcome of CRT is unclear.The purpose of this study was to evaluate whether heart failure etiology (ischemic cardiomyopathy [ICM] vs nonischemic dilated cardiomyopathy [DCM]) was associated with CRT outcome and implantable cardioverter-defibrillator (ICD) shocks.The study included 503 CRT recipients (CRT-D 90%) in a longitudinal CRT database: ICM (n = 312) and DCM (n = 191). Clinical variables and echocardiographic measures preimplant and postimplant were collected. Actuarial survival and ICD therapy data were assessed with Kaplan-Meier curve and log rank tests.Pre-CRT, ICM patients were older and had higher creatinine levels (P.001). At median follow-up of 7.1 months, the DCM group experienced greater improvement in left ventricular ejection fraction (8.3% ± 10% vs 6.2% ± 10%, P = .05) and left ventricular end-diastolic volumes than did those with ICM (-28%.4 ± 53 mL vs -15.3 ± 46 mL, P = .024). Survival estimates at 4 years were 55% for ICM and 77% for DCM groups (P.001), respectively, whereas no significant difference in the incidence of appropriate/inappropriate ICD shocks was observed. The ICM group remained at higher risk for death compared to the DCM group after controlling for preimplant variables (hazard ratio 1.6, 95% confidence interval 1.1-2.3, P = .008).In response to CRT and in contrast to ICM, DCM patients experienced greater improvement in left ventricular systolic function and reverse remodeling while also sustaining a greater survival benefit.

Ablation eliminates atrial fibrillation (AF) in studies with 1 year follow-up, but very late recurrences may compromise long-term efficacy. In a large cohort, we sought to describe the determinants of delayed recurrence after AF ablation.Seven hundred and seventy-four patients with AF (428 paroxysmal [PAF, 55%] and 346 persistent or longstanding persistent [PersAF, 45%]) underwent wide area circumferential ablation (WACA, 62%) or pulmonary vein isolation (38%). Over 3.0 ± 1.9 years, there were 135 recurrences in PAF patients and 142 in PersAF patients. AF elimination was achieved in 61% of patients with PersAF at 2 years after last ablation and in 71% of patients with PAF (P = 0.04). This finding was related to a higher initial rate of very late recurrence in PersAF. From 1.0 to 2.5 years, the recurrence increased by 20% (from 37% to 57%) in PersAF patients versus only 12% (from 27% to 39%) in PAF patients. Independent predictors of overall recurrence included diabetes (HR 1.9 [1.3-2.9], P = 0.002) and PersAF (HR 1.6 [1.2-2.0], P0.001). Independent predictors of very late recurrence included PersAF (HR 1.7 [1.1-2.7], P = 0.018) and WACA (HR 1.8 [1.1-2.7], P = 0.018), while diabetes came close to significance. In PAF patients, left atrial size45 mm was identified as an AF-type specific predictor (HR 2.4 [1.3-4.7], P = 0.009), whereas in PersAF patients, no unique predictors were identified.Late recurrences reduced the long-term efficacy of AF ablation, particularly in patients with PersAF and underlying cardiovascular diseases.

The past decade has seen a dramatic increase in efforts by both payors and governmental agencies to measure and publicly report patient outcomes to ensure that patients receive appropriate, high-quality care. As a result, terms such as outcomes, quality, report cards, and benchmarking have entered the lexicon of clinical medicine, and both physicians and hospitals are increasingly being held accountable for the outcomes of their patients. This movement shows no sign of slowing down. In May 2008, the Centers for Medicare and Medicaid Services proposed increasing the total number of inpatient hospital measures from 40 to 73,1 and numerous physician measures are in various phases of development. In the current environment, it is likely that implantable cardioverter defibrillators (ICDs), which reduce the risk of sudden cardiac death,2 will soon emerge as a high-priority target for the development of performance measures, given that the procedure is expensive, performed on severely ill patients, and associated with significant risk of complications. Article see p 240 Accordingly, the findings published by Al-Khatib et al3 in this issue of Circulation: Arrhythmia and Electrophysiology warrant consideration in the context of current efforts to publicly report patient outcomes using Medicare claims data. In this excellent article, the authors used data from Centers for Medicare and Medicaid Services standard analytic files to determine the 90-day postprocedure complication rates and 1-year mortality rates of 8581 Medicare beneficiaries who had an ICD implanted by one of 1959 implanting physicians. The authors note that the complication rate declined from 18.8% in 2002 to 14.2% in 2005 and further identified specific factors associated with an increased risk of complication such as chronic lung disease, dementia, and renal disease. Of interest, physician experience as measured by procedure volume was not significantly associated with the risk of complication, although an earlier …

Background— Outflow tract ventricular tachycardia originating above the semilunar valves has been reported in a small number of studies. Discrete potentials in the great arteries (above the semilunar valves) have been rarely described in patients undergoing electrophysiology evaluation and radiofrequency ablation for ventricular arrhythmias. The mechanisms of these discrete potentials in the great arteries and the utility of such potentials in guiding radiofrequency ablation are unknown. Methods and Results— Twelve patients with outflow tract ventricular arrhythmia originating above the semilunar valves with discrete arterial potentials were studied. The clinical characteristics, properties of the arterial potentials, electrophysiological evaluation and ablation, and short- and long-term outcomes were reviewed. Of the twelve patients, 8 (67%) were women. The patients’ average age was 41�14 years. The average ejection fraction was 0.52�0.16 (range: 0.16 to 0.75). Contact mapping in the great artery demonstrated discrete near-field electrograms that were separate from far-field ventricular electrograms in all patients (8 above the pulmonary valve and in 4 the aortic valve). One or more of the following electrophysiological characteristics, supportive of an arrhythmogenic substrate, were observed in 10 of 12 patients: (1) A fixed or reproducibly variable pattern of discrete potential–ventricular arrhythmia relationship was present at baseline or during pacing; (2) the discrete potential–ventricular electrogram relationship during sinus rhythm was the reverse of that during the ventricular arrhythmia; (3) during sustained ventricular tachycardia, spontaneous variation of the ventricular (V-V) cycle length was preceded by a similar variation of arterial spike potential–spike potential cycle length; and (4) ablation guided by the discrete arterial potential successfully eliminated the clinical arrhythmia. Ablation was successful in these patients. In the remaining 2 patients, the potentials were believed to be bystanders. Over 10�4 months (range: 5 to 32 months) of follow-up, there have been no recurrences of the premature ventricular complex or ventricular arrhythmia. Conclusions— Discrete potentials are present in the great arteries of a select group of patients with outflow tract ventricular tachycardia originating above the semilunar valves. When an arrhythmogenic relationship can be demonstrated, discrete potentials are useful in guiding ablation within the great vessels, despite significant anatomic complexity.

Background— The risk of syncope occurring while driving has obvious implications for personal and public safety. We aimed to define the clinical characteristics, causes, and prognosis of syncope while driving. Methods and Results— In this case-control study of consecutive patients evaluated for syncope from 1996 through 1998 at an academic medical center, we documented causes, clinical characteristics, and recurrence of syncope while driving. Of 3877 patients identified, 381 (9.8%) had syncope while driving (driving group). Compared with the 3496 patients (90.2%) who did not have syncope while driving, the driving group was younger ( P =0.01) and had higher percentages of male patients ( P P =0.01) and stroke ( P =0.02). Syncope while driving was commonly caused by neurally mediated syncope (37.3%) and cardiac arrhythmias (11.8%). Long-term survival in the driving group was comparable to that of an age- and sex-matched cohort from the Minnesota population ( P =0.15). Among the driving group, syncope recurred in 72 patients, 35 of whom (48.6%) had recurrence >6 months after the initial evaluation. Recurrences during driving happened in 10 patients in the driving group, 7 of which (70%) were >12 months after the initial evaluation. Conclusions— In our study, neurally mediated syncope was the most common type of syncope while driving. The causes of syncope, the late recurrences of syncope (during ≥6 months of follow-up), and the overall low incidence of recurrent syncope while driving provide useful information to supplement current recommendations on driving for these patients.

Allowing nonelectrophysiologists to perform implantable cardioverter-defibrillator (ICD) procedures is controversial. However, it is not known whether outcomes of ICD implantation vary by physician specialty.To determine the association of implanting physician certification with outcomes following ICD implantation.Retrospective cohort study using cases submitted to the ICD Registry performed between January 2006 and June 2007. Patients were grouped by the certification status of the implanting physician into mutually exclusive categories: electrophysiologists, nonelectrophysiologist cardiologists, thoracic surgeons, and other specialists. Hierarchical logistic regression models were developed to determine the independent association of physician certification with outcomes.In-hospital procedural complication rates and the proportion of patients meeting criteria for a defibrillator with cardiac resynchronization therapy (CRT-D) who received that device.Of 111,293 ICD implantations included in the analysis, 78,857 (70.9%) were performed by electrophysiologists, 24,399 (21.9%) by nonelectrophysiologist cardiologists, 1862 (1.7%) by thoracic surgeons, and 6175 (5.5%) by other specialists. Compared with patients whose ICD was implanted by electrophysiologists, patients whose ICD was implanted by either nonelectrophysiologist cardiologists or thoracic surgeons were at increased risk of complications in both unadjusted (electrophysiologists, 3.5% [2743/78,857]; nonelectrophysiologist cardiologists, 4.0% [970/24,399]; thoracic surgeons, 5.8% [108/1862]; P.001) and adjusted analyses (relative risk [RR] for nonelectrophysiologist cardiologists, 1.11 [95% confidence interval {CI}, 1.01-1.21]; RR for thoracic surgeons, 1.44 [95% CI, 1.15-1.79]). Among 35,841 patients who met criteria for CRT-D, those whose ICD was implanted by physicians other than electrophysiologists were significantly less likely to receive a CRT-D device compared with patients whose ICD was implanted by an electrophysiologist in both unadjusted (electrophysiologists, 83.1% [21 303/25,635]; nonelectrophysiologist cardiologists, 75.8% [5950/7849]; thoracic surgeons, 57.8% [269/465]; other specialists, 74.8% [1416/1892]; P.001) and adjusted analyses (RR for nonelectrophysiologist cardiologists, 0.93 [95% CI, 0.91-0.95]; RR for thoracic surgeons, 0.81 [95% CI, 0.74-0.88]; RR for other specialists, 0.97 [95% CI, 0.94-0.99]).In this registry, nonelectrophysiologists implanted 29% of ICDs. Overall, implantations by a nonelectrophysiologist were associated with a higher risk of procedural complications and lower likelihood of receiving a CRT-D device when indicated compared with patients whose ICD was implanted by an electrophysiologist.

Coronary artery disease is the leading cause of death in the United States. Approximately half of the deaths attributable to coronary artery disease are sudden cardiac deaths. A logical approach to prevention of sudden death is to identify those who are at risk and then to initiate effective therapy. Left ventricular dysfunction, frequent ventricular ectopic activity, nonsustained ventricular tachycardia, and late potentials have been identified as markers for increased risk of sudden cardiac death. The sensitivity and specificity of these risk factors vary, and the positive predictive power is less than satisfactory. The value of invasive electrophysiologic testing for risk stratification in the general postinfarction patient population remains unclear. In addition to these diagnostic difficulties, prevention of sudden death also has been limited by imperfect efficacy and potential lethal effects of the currently available antiarrhythmic agents. Automatic implantable defibrillators are effective for aborting sudden death; however, the potential for more general use of automatic defibrillators in asymptomatic but high-risk postinfarction patients has not been evaluated.

Determining whether retrograde ventriculoatrial (VA) conduction is through the AV node (AVN) or an accessory pathway (AP) is critical for successful ablation of supraventricular tachycardia (SVT). With introduction of ventricular extrastimuli (VEST), retrograde right bundle branch block (retro RBBB) may occur and result in abrupt VH interval prolongation. We hypothesized when retrograde conduction is via an AP, VA interval change is less than VH interval change, whereas with retrograde AVN conduction, VA interval change is equal to or greater than VH interval change. We retrospectively reviewed the electrophysiology (EP) studies of patients undergoing ablation for AVNRT (n=55) or AVRT (n=50). The intracardiac electrograms were reviewed for induction of retro RBBB and change in VH and VA intervals during VEST. Parahisian pacing, decremental pacing, arrhythmia diagnosis and ablation outcomes were reviewed. All results were found to be reproducible between two independent observers with inter and intra observer reliability scores of 1.00 for identification of retro RBBB and greater than 0.85 for measurement of VH and VA intervals. Of 105 patients, 84 (80%) had evidence of induced retro RBBB during VEST. The average VH interval increase with induction of retro RBBB was 53.7 ms for patients with retrograde AP conduction and 54.4 ms for patients with AVN conduction (p=ns). The average VA interval increase with induction of retro RBBB was 13.6 ms with AP conduction and 70.1 ms with AVN conduction (P < 0.001). All patients with a greater VH than VA interval change had a final diagnosis of AVRT and those with a VH change less than VA change had AVNRT, yielding sensitivity and specificity of 100%. Using a cutoff of 50 ms for change in VA interval with onset of retro RBBB to diagnose AVNRT accurately identified AVNRT in 100% and AVRT in 95%. Induction of retro RBBB during VEST is common during EP studies for SVT. The relative change in the VH and VA intervals during retro RBBB accurately differentiates retrograde AVN from retrograde AP conduction with strong predictive accuracy. The use of retro RBBB based intervals is a useful technique facilitating the diagnosis of SVT in the EP laboratory, even in the absence of inducible tachycardia.

Objectives We sought to determine the frequency and outcomes with symptomatic arrhythmia in patients with apical ballooning syndrome (ABS). Methods A retrospective review of the Mayo Clinic Angiography database was conducted to identify patients who met the Mayo criteria for ABS. Patients with documented arrhythmias formed the study group, and 31 randomly selected patients with ABS but without arrhythmia formed the control group. Results Out of 105 patients identified with ABS, 6 (5.7%) women aged 69 +/- 9 years experienced significant arrhythmia (ventricular fibrillation, asystole), 2 patients died, and 1 required permanent pacemaker implantation. When compared with controls, the study group showed no significant difference with respect to ECG characteristics (QT, QRS duration or axis) except for R-R interval variability (see comments below) (30.6±6 vs 14.5±17 p = 0.0004), QTc, and P-R interval. Patients without arrhythmia were more likely to be on beta-blocker therapy than the study population (33% vs 80.6% p = 0.02). Conclusion Life-threatening arrhythmia is uncommon (5.7%) with ABS despite marked, structural abnormalities. When arrhythmias do occur, the outcome is poor. Prominent variability in R-R intervals appears to be predictive of significant arrhythmias in ABS. The role of beta-blocker therapy in preventing arrhythmia with ABS requires further investigation.

esenc F d m l b t G t N d s Q o M N h a c p i t t i e r i e t a e y p c e t t b T t ntroduction he National ICD Registry became the sole repository of CD implantation data for Medicare beneficiaries April 1, 006 and as of June 2008 had collected data from 1,448 ospitals in the United States totaling over 270,373 imlants. This registry was developed through a partnership of he Heart Rhythm Society (HRS; www.HRSonline.org) and he American College of Cardiology Foundation (ACCF; ww.acc.org) utilizing the expertise of the National C iovascular Data Registry (NCDR; www.accncdr.com). he National ICD Registry is accruing ICD implants at the ate of 10,000 per month with 88% of implants being done n hospitals that enter all patients receiving ICDs including oth primary and secondary prevention indications in all ge groups. A rigorous Data Quality Reporting process is in lace to ensure data accuracy and hospital auditing will egin the summer of 2008. Six abstracts have been pr ed, and four manuscripts are in development utilizing ata generated from the National ICD Registry answering ey clinical questions elicited from the growing ICD imlant patient database ( http://www.accncdr.com). Funding or the Longitudinal ICD Registry Study has been procured, nd the study will begin in 2008. The scope of the National CD registry is being expanded to include data on new trial, ventricular, defibrillation, and left-heart leads placed t the time of ICD implant and whenever existing leads are epositioned, replaced, extracted or abandoned. These data ill assist the Food and Drug Administration (FDA) with urveillance of lead performance. Pediatric ICD implantaions will be followed in the Registry; and the Registry is eing positioned to serve as a performance reporting tool to ssist with quality measures.

2008;51;2085-2105; originally published online May 15, 2008; J. Am. Coll. Cardiol. Michael O. Sweeney L. Page, Mark H. Schoenfeld, Michael J. Silka, Lynne Warner Stevenson, and Stephen C. Hammill, David L. Hayes, Mark A. Hlatky, L. Kristin Newby, Richard Roger A. Freedman, Leonard S. Gettes, A. Marc Gillinov, Gabriel Gregoratos, Andrew E. Epstein, John P. DiMarco, Kenneth A. Ellenbogen, N.A. Mark Estes, III, Surgery and Society of Thoracic Surgeons Developed in Collaboration With the American Association for Thoracic for Implantation of Cardiac Pacemakers and Antiarrhythmia Devices) (Writing Committee to Revise the ACC/AHA/NASPE 2002 Guideline Update Cardiology/American Heart Association Task Force on Practice Guidelines Abnormalities: Executive Summary: A Report of the American College of ACC/AHA/HRS 2008 Guidelines for Device-Based Therapy of Cardiac Rhythm This information is current as of June 4, 2010 http://content.onlinejacc.org/cgi/content/full/51/21/2085 located on the World Wide Web at: The online version of this article, along with updated information and services, is

ST-segment depression in the absence of symptoms is now a well-defined abnormality in patients with coronary artery disease. ST-segment depression without the occurrence of angina is a marker for myocardial perfusion defects and ischemia. During 24-hour recordings, most episodes of ischemia in patients with coronary artery disease are silent and occur with relatively normal heart rates. The combination of silent ischemia and ischemia associated with angina is referred to as total ischemic burden. Silent ischemia is prognostically important for identifying patients in whom subsequent myocardial events may develop. The episodes of silent ischemia, and thus total ischemic burden, can be reduced by standard antianginal therapy, a measure that may have a favorable influence on patient outcome. Proof that reduction of the total ischemic burden actually improves outcome, however, is not yet available.

To improve the predictive accuracy of the signal-averaged electrocardiogram, we created a linear logistic model for predicting ventricular tachycardia during electrophysiologic testing. This signal-averaged electrocardiographic model was created from data obtained from 214 patients undergoing electrophysiologic testing (70 had ventricular tachycardia during electrophysiologic testing) by using stepwise logistic regression to rank eight clinical and nine signal-averaged electrocardiographic variables. The best predictors were ejection fraction, history of infarction, ventricular ectopic pairs or nonsustained ventricular tachycardia on Holter monitoring, QRS duration after 25-Hz filtering, and root mean square voltage of the terminal 40 msec of the QRS complex after 40- and 80-Hz filtering. Cross validation (a statistical technique that can be used to accurately evaluate how a predictive model will perform on a prospective patient population) was used to validate the model. After cross validation, the model's sensitivity was 91% and specificity was 59% for predicting ventricular tachycardia during electrophysiologic testing. This model compared favorably with established 25-Hz late-potential criteria (QRS duration of more than 110 msec and root mean square voltage of less than 25 microV of the terminal 40 msec of the QRS complex; sensitivity, 64%; specificity, 85%) and with established 40-Hz late-potential criteria (QRS duration of more than 114 msec or root mean square voltage of less than 20 microV of the terminal 40 msec of the QRS complex or duration of the low-amplitude signal less than 40 microV at the terminal QRS complex that is greater than 38 msec; sensitivity, 84%; specificity, 54%).(ABSTRACT TRUNCATED AT 250 WORDS)

Summary The signal-averaged ECG has proven to be a valuable tool for identifying patients at risk of ventricular arrhythmias. This computerized method of analyzing standard ECGs identifies microvolt-level late potentials that represent delayed conduction through diseased myocardium. This diseased myocardium is a potential substrate for reentrant ventricular arrhythmias. In select patient groups, the signal-averaged ECG predicts electrophysiologic testing results. Problems remain and continued development is needed to evaluate patients with conduction system disease, the patient without coronary artery disease but at risk of sudden death, and proper general application of the technique.

Background : Lipid lowering therapy reduces mortality in patients with both ischemic and nonischemic cardiomyopathies and recently has been shown to decrease ICD shocks. Radiofrequency ablation (RFA) of recurrent VT in patients with an ICD also reduces shocks following intervention. It is unclear if statin therapy after VT RFA will further impact ICD shock rates. Methods : All patients from 1993–2005 who underwent a RFA procedure for recurrent VT at the Mayo Clinic with an ICD were included. Patient records were extracted for medical and procedural details and all ICD interrogations were reviewed for VT recurrence and therapies. Results: 63 patients (age 62±15 years) were followed over 3.9±3.6 years. Comorbid diseases included: coronary artery disease 37(58%, 34 prior myocardial infarction), ARVD/C 6(10%), nonischemic dilated cardiomyopathy 7(11%), moderate-severe valve disease 14(22%), hypertension 34(54%), and hyperlipidemia 35(56%). Ejection fraction was Conclusion : Statin use at discharge in patients with an ICD undergoing RFA for refractory VT significantly reduced recurrent ventricular arrhythmias and ICD shocks. Although the mechanism underlying the effects of statins on arrhythmic recurrence early after RFA requires further study, these data support aggressive therapy of the underlying substrate responsible for the VT.

O N T a d p o ntroduction he National ICD Registry was developed through a partnerhip of the American College of Cardiology Foundation ACCF) and the Heart Rhythm Society (HRS) utilizing the xpertise of the National Cardiovascular Data Registry NCDR). The National ICD Registry became the sole reposiory of ICD implantation data for Medicare beneficiaries startng April 1, 2006, and, as of July 2007, had collected data from ,318 hospitals in the United States totaling over 160,000 mplants. The number of ICD implants in the National ICD egistry is accruing at a rate of 10,000 per month with 88% of mplants being done in hospitals that are entering all patients ho are receiving an ICD (both primary and secondary preention indications and all age groups). The rigorous Data uality Reporting (DQR) process is in place which helps to nsure data accuracy. The ICD Registry Research and Publiations Committee selects submitted research proposals poised o answer key clinical questions elicited from the growing ICD mplant patient data base. As the next step to provide enhanced ontext for device outcomes, the Longitudinal ICD Registry tudy design has now been developed and approved by the enter for Medicare and Medicaid Services (CMS). This reiew will highlight the activities of the National ICD Registry uring 2006, its first year of operation, report an overview of he data that has been collected, and summarize the future lans for the Registry.

Background— The long-term natural history of lone atrial fibrillation is unknown. Our objective was to determine the rate and predictors of progression from paroxysmal to permanent atrial fibrillation over 30 years and the long-term risk of heart failure, thromboembolism, and death compared with a control population. Methods and Results— A previously characterized Olmsted County, Minnesota, population with first episode of documented atrial fibrillation between 1950 and 1980 and no concomitant heart disease or hypertension was followed up long term. Of this unique cohort, 76 patients with paroxysmal (n=34), persistent (n=37), or permanent (n=5) lone atrial fibrillation at initial diagnosis met inclusion criteria (mean age at diagnosis, 44.2±11.7 years; male, 78%). Mean duration of follow-up was 25.2±9.5 years. Of 71 patients with paroxysmal or persistent atrial fibrillation, 22 had progression to permanent atrial fibrillation. Overall survival of the 76 patients with lone atrial fibrillation was 92% and 68% at 15 and 30 years, respectively, similar to 86% and 57% survival for the age- and sex-matched Minnesota population. Observed survival free of heart failure was slightly worse than expected ( P =0.051). Risk for stroke or transient ischemic attack was similar to the expected population risk during the initial 25 years of follow-up but increased thereafter ( P =0.004), although CIs were wide. All patients who had a cerebrovascular event had developed ≥1 risk factor for thromboembolism. Conclusions— Comorbidities significantly modulate progression and complications of atrial fibrillation. Age or development of hypertension increases thromboembolic risk.

Introduction: Our objective was to determine features of ventricular tachyarrhythmias triggering appropriate implantable cardioverter-defibrillator (ICD) interventions in hypertrophic cardiomyopathy (HCM). Methods and Results: The study cohort was 68 high-risk HCM patients who received ICDs for primary sudden cardiac death prevention from 1995 to 2003. All episodes of sustained ventricular tachyarrhythmias identified by stored intracardiac electrograms were analyzed. Nine patients had 51 episodes of sustained ventricular tachyarrhythmic events that required device therapy (mean follow-up, 3.4 ± 2.2 years; cumulative event rate, 3.2% per year): five had 47 episodes of monomorphic ventricular tachycardia (VT); four each had one episode of ventricular fibrillation (VF). Sinus tachycardia or atrial fibrillation was the initiating rhythm in five of nine patients and in 43 of 51 episodes of events. Of the 17 episodes of monomorphic VT detected in the VT zone, 16 (94%) were terminated by antitachycardia pacing. Thirty episodes of monomorphic VT were detected in the VF zone and were terminated by defibrillation. Conclusion: Sustained monomorphic VT is common in a high-risk cohort with HCM. Sinus tachycardia is often the initiating rhythm, suggesting that high sympathetic drive may be proarrhythmic when a susceptible substrate is present. Antitachycardia pacing is highly effective in terminating VT in this patient population.

Hypertrophic cardiomyopathy (HC) often presents with exercise-induced symptoms, including arrhythmias and sudden death. The investigators prospectively studied whether exercise testing is associated with immediate complications and if stress-induced arrhythmias and echocardiographic variables are associated with long-term adverse outcomes. Exercise echocardiography with 6-channel continuous monitoring for arrhythmias was performed in consecutive patients with HC clinically referred for the test. End points included death, myocardial infarction, revascularization, stroke, atrial fibrillation, ventricular tachycardia, and myectomy. Of 86 patients with HC (mean age 56.6 +/- 16.1 years) who underwent exercise echocardiography, arrhythmias occurred in 39 (45%), including 23 (27%) with premature atrial contractions, 2 (2%) with atrial fibrillation, 28 (33%) with premature ventricular contractions (16 also had atrial arrhythmias), and 1 (1.2%) with nonsustained ventricular tachycardia (hemodynamically stable). During a follow-up of 2.6 +/- 2.8 years, major events occurred in 11 patients (3 deaths, 5 revascularizations, 3 strokes). In addition, 12 patients developed atrial fibrillation, 6 developed nonsustained ventricular tachycardia, and 13 underwent myectomies. Variables associated with major events included hypertension, male gender, and worsening wall motion score index with exercise; increased exercise duration was associated with fewer events. ST-T changes on baseline electrocardiography and premature ventricular contractions were associated with atrial fibrillation risk. In conclusion, in this cohort of patients with HC, exercise testing was safe. Test results were associated with risk for adverse events.

Background The effect of patient sex on recurrence of atrial fibrillation after a successful direct current cardioversion is unknown. Methods This prospective study included 773 patients (486 [63%] men and 287 [37%] women) undergoing successful direct current cardioversion of atrial fibrillation between May 2000 and July 2003. Patient characteristics at presentation were recorded. The primary end point was the time between cardioversion and the first documented recurrence of arrhythmia. Results At presentation, women were older and had a higher prevalence of hypertension and valvular disease compared with men. In addition, women had worse mechanical left atrial appendage function. Arrhythmia recurrence was more prevalent in women (50.0% at 1 year compared with 43.4% in men, and 75.8% at 2 years compared with 67.0% in men; P = .03). On the basis of multivariate analysis, patient sex was a significant predictor of arrhythmia recurrence. There was no significant difference in overall mortality between men and women. Conclusions Women were more likely than men to have recurrence of atrial fibrillation after successful direct current cardioversion. Patient sex should be taken into account with other clinical factors when making the decision about cardioversion for atrial fibrillation.