When Cardioversion May Be Complicated.

BACKGROUND: In recent years cardioversion of atrial fibrillation has become a routine procedure, enabling symptomatic functional improvement in most cases. However, some patients develop complications after cardioversion. Identifying these individuals is an important step toward improving patient outcome. OBJECTIVES: To characterize those patients who may not benefit from cardioversion or who may develop complications following cardioversion. METHODS: We retrospectively analyzed 186 episodes of cardioversion in 163 patients with atrial fibrillation who were admitted to our cardiology department between 2008 and 2013 based on their clinical and echocardiographic data. Patients were divided into two groups: those with uncomplicated cardioversion, and those who developed complications after cardioversion. RESULTS: Of the 186 episodes, cardioversion was done in 112 men (60%) and 74 women (40%), P < 0.00001. Complications after cardioversion occurred in 25 patients (13%). These patients were generally older (72 vs. 65 years, P < 0.01), were more often diabetic (52% vs. 27%, P = 0.005), had undergone emergency cardioversion (64% vs. 40%, P = 0.01), had left ventricular hypertrophy (left ventricular mass 260 vs. 218 g, P = 0.01), had larger left atrium (left atrial volume 128 vs. 102 ml, P < 0.009), and more often died from complications of cardioversion (48% vs. 16%). They had significant mitral regurgitation (20% vs. 4%, P = 0.03) and higher pulmonary artery pressure (50 vs. 42 mm Hg, P < 0.02). CONCLUSIONS: People with complications after cardioversion tend to be older, are more often diabetic and more often have severe mitral regurgitation. In these patients, the decision to perform cardioversion should consider the possibility of complications.

Atrial Tachycardia in Patients with Cryptogenic Stroke: Is there a Need For Anticoagulation?

BACKGROUND: Brief episodes of atrial tachycardia are a common finding in the Holter monitor recordings of elderly patients. Episodes of atrial tachycardia may convert to atrial fibrillation. Current guidelines do not recommend anti-coagulant therapy in patients with atrial tachycardia and risk factors for embolism. OBJECTIVES: To assess the incidence of atrial tachycardia in a 24 hour Holter monitor recording of patients admitted to hospital with ischemic stroke. METHODS: The patient cohort included two groups: 134 patients admitted with a diagnosis of ischemic stroke (the study group), and 68 consecutive patients with a diagnosis of syncope (the control group). Both groups used a Holter monitor. RESULTS: There was no difference in the incidence of atrial tachycardia runs between the groups. Patients who suffered a stroke were more likely to be hypertensive (P < 0.05) and more likely to have a CHA2DS2-VASc score of ≥ 3 (P = 0.05). CONCLUSIONS: Atrial tachycardia as recorded on a Holter monitor was not more prevalent in patients presenting with ischemic stroke. The occurrence of atrial tachycardia is not an indication for systemic anticoagulation.

Clinical characteristics and outcomes of elderly patients treated with an implantable cardioverter-defibrillator or cardiac resynchronization therapy in a real-world setting: data from the Israeli ICD Registry.

BACKGROUND: Elderly patients are underrepresented in clinical trials of device therapy. OBJECTIVE: To provide real-world data regarding outcomes associated with device-based therapy in a large cohort of elderly patients enrolled in the Israeli ICD Registry. METHODS: Between July 2010 and June 2012, a total of 2807 consecutive patients undergoing implanted cardioverter-defibrillator/cardiac resynchronization therapy-defibrillator (ICD/CRT-D) implantation were prospectively enrolled in the Israeli ICD Registry. For the present analysis, patients were categorized into 3 age groups: ≤60 years (n = 1378 [49%]), 61-75 years (n = 863 [31%]), and >75 years (n = 566 [20%]). RESULTS: Elderly patients (>75 years of age) had more comorbid conditions and were more likely to undergo CRT-D implantation (all P < .01). However, the rate of device-related complications associated with surgical reinterventions at 1 year was <3% regardless of age (P = .70 for the comparison among the 3 age groups). Multivariate analysis showed that the risk of heart failure or death and of appropriate ICD therapy for ventricular arrhythmias was significantly increased with increasing age among patients who received an ICD. In contrast, the age-related increase in the risk of all end points was attenuated among patients who received CRT-D devices (all P values for age-by-device-type interactions are <.05). CONCLUSIONS: In a real-world scenario, elderly patients (>75 years of age) comprise approximately 20% of the ICD/CRT-D recipients and experience a device reintervention rate similar to that of their younger counterparts. Our data suggest that the association between advanced age and adverse clinical outcomes is attenuated in elderly patients implanted with CRT-D devices.

Do ventricular arrhythmias in athletes subside over time?

BACKGROUND: Sudden death in athletes can occur during sport activities and is presumably related to ventricular arrhythmias. OBJECTIVES: To investigate the long-term follow-up ofathletes with ventricular arrhythmias during an exercise test. METHODS: From a database of 56,462 athletes we identified 192 athletes (35 years old who had ventricular arrhythmias during an exercise test. Ninety athletes had > or =3 ventricular premature beats (VPB) (group A) and 102 athletes had ventricular couplets or non-sustained ventricular tachycardia during an exercise test (group B). A control group of 92 athletesfrom without ventricular arrhythmias was randomly seleclted from the database (group C). Of the 192 athletes 39 returnied for a repeat exercise test after a mean follow-up period of 70 +/- 25 months and they constitute the study population. RESULTS: Twelve athletes from group A, 21 fromgroup B and 6 from group C returned for a repeat exercise test. The athletes reached a significantly lower peak heart rate during their follow-up exercise test (P = 0.001). More athletes were engaged in competitive sports during their initialexercise test than in the follow-up test (P = 0.021). Most of theathletes who had VPB and/orventricular couplets and/or NSVT during their initial exercise test had far fewer ventricular arrhythmias in the follow-up exercise test (P = 0.001). CONCLUSIONS: Athletes engaged in competitive sports are more likely to develop ventricular arrhythmias during exercise. These arrhythmias subside over time when athletes are engaged in non-competitive sports.

Does chronic atrial fibrillation induce cardiac remodeling?

AIM: The aim of this study was to compare cardiac structure and function in patients with chronic atrial fibrillation (CAF), as opposed to patients with paroxysmal atrial fibrillation (PAF), and normal control subjects. METHODS AND RESULTS: This study included 83 patients, divided into 3 groups: group A, 32 patients with CAF for ≥6 months; group B, 29 patients in sinus rhythm with a documented history of PAF; and group C, 22 patients without history of atrial fibrillation. Patients with CAF were older (71 years vs. 64 in group B, and 64 in group C). Apart from age, groups were clinically similar. After careful clinical evaluation, comprehensive echocardiography studies were performed including cardiac chambers' size, systolic and diastolic left ventricular function. Left atrium (LA) volume index was significantly larger in CAF than PAF and control patients: 39 ± 13 versus 34 ± 9 versus 25 ± 8 (P < 0.003). Left ventricular ejection fraction was lower in CAF: 53.8 ± 7 versus 61.6 ± 6.7 versus 58.4 ± 5.2% (P < 0.001). Isovolumic relaxation time was shorter in CAF, 65 ± 16 versus 82 ± 21 versus 81 ± 13 msec (P < 0.001). E/Vp was significantly greater in CAF 2.6 ± 0.8 versus 1.7 ± 0.4 versus 1.7 ± 0.5 (P < 0.001). Additional diastolic parameters were also significantly different. CONCLUSION: These findings demonstrate that in patients with CAF structural and functional cardiac changes occur. Patients with CAF as opposed to both normal subjects and patients with PAF have larger left atria and reduced systolic and diastolic left ventricular function.

Reproducibility of microvolt T-wave alternans in patients with coronary artery disease.

BACKGROUND: Microvolt T-wave alternans (MTWA) measures subtle beat-to-beat fluctuations in the T-wave amplitude. It was found to be associated with cardiac electrical instability in patients with ischemic and dilated cardiomyopathy. OBJECTIVES: To investigate the reproducibility of the MTWA test results in patients with ischemic heart disease. METHODS: The study group comprised patients with ischemic heart disease who participated in a rehabilitation program at the Assaf Harofeh Medical Center. MTWA was measured during a bicycle exercise test at the first encounter and repeated after one week. RESULTS: Of the 40 study patients with coronary artery disease, 4 had an indeterminate result and were excluded from the data analysis; 5 had a positive MTWA in the first and second study (14%), 27 had a negative MTWA in the first and second study (75%), and 4 had a negative MTWA in the first study and a positive MTWA in the second study (11%). Overall, there was a correlation between the results of the first and the second study in 89% of the patients (kappa = 0.652, P = 0.0001). CONCLUSIONS: MTWA measurements are reproducible in the short term in patients with coronary artery disease.

Vegetation size in patients with infective endocarditis.

AIMS: Infective endocarditis is a serious disease with diverse clinical manifestations. The aim of this work was to analyse vegetations' size in relation to the clinical presentation, course of the disease, and the type of the microorganism. METHODS AND RESULTS: A total of 146 patients with definite diagnosis of infective endocarditis were identified at Assaf Harofeh Medical Center during the years 1998 to 2010. Of them in 102 patients accurate vegetations' size was available. The data of these patients were collected and analysed. Twenty-three per cent of patients died, embolic complications occurred in 20.6% of patients, 16% of patients underwent surgery. Large vegetations (≥1 cm) occurred in 46 patients. Older patients (>60 years) with large vegetations had significantly increased risk of mortality 38% (P< 0.05). The strongest independent predictor of mortality was MRSA endocarditis (45%, P= 0.01), followed by staphylococcal endocarditis associated with large vegetations (43%, P= 0.01), or with older age (41%, P= 0.01). The combination of staphylococcal endocarditis with large vegetations in the older patients was associated with mortality risk of 50%, P= 0.02. Large vegetations were associated with high incidence of abscess formation (17%, P< 0.001), especially in combination with MRSA (27%, P= 0.01), diabetes (25%, P< 0.02), and older age (30%, P= 0.01). CONCLUSION: Our results indicate that in patients with infective endocarditis the strongest predictor of mortality is MRSA infection, followed by staphylococcal infection especially in association with older age or with large vegetations. Older patients with large vegetations are also in significant risk of mortality. In these groups of patients surgery should be considered early.

Speckle tracking imaging in acute inflammatory pericardial diseases.

BACKGROUND: Left ventricular (LV) function in acute perimyocarditis is variable. We evaluated LV function in patients with acute perimyocarditis with speckle tracking. METHODS: Thirty-eight patients with acute perimyocarditis and 20 normal subjects underwent echocardiographic examination. Three-layers strain and twist angle were assessed with a speckle tracking. Follow-up echo was available in 21 patients. RESULTS: Strain was higher in normal subjects than in patients with perimyocarditis. Twist angle was reduced in perimyocarditis--10.9° ± 5.4 versus 17.6° ± 5.8, P < 0.001. Longitudinal strain and twist angle were higher in normal subjects than in patients with perimyocarditis and apparently normal LV function. Follow-up echo in 21 patients revealed improvement in longitudinal strain. CONCLUSIONS: Patients with acute perimyocarditis have lower twist angle, longitudinal and circumferential strain. Patients with perimyocarditis and normal function have lower longitudinal strain and twist angle. Short-term follow-up demonstrated improvement in clinical parameters and longitudinal strain despite of residual regional LV dysfunction.

The clinical significance of ventricular arrhythmias during an exercise test in non-competitive and competitive athletes.

BACKGROUND: Sudden death in athletes can occur during sport activities and is presumably related to ventricular arrhythmias. There are no guidelines concerning athletes who develop ventricular arrhythmias during an exercise test. It is unclear whether they should be allowed to continue with their competitive activity or not. OBJECTIVES: To investigate the long-term follow-up of athletes with ventricular arrhythmias during an exercise test. METHODS: From a database of 56,462 athletes we identified 192 athletes, less than 35 years old, who had ventricular arrhythmias during an exercise test. Ninety athletes had > or = 3 ventricular premature beats (group A) and 102 athletes had ventricular couplets or non-sustained ventricular tachycardia during an exercise test (group B). A control group of 92 athletes without ventricular arrhythmias was randomly selected from the database (group C). RESULTS: All athletes, except one who died from a dilated cardiomyopathy, were alive during a follow-up period of 70 +/- 25 months. An abnormal echocardiogram was obtained in seven athletes from group A (10%), four from group B (5%), and one from group C (3%) (not significant). An abnormal echocardiogram was more likely to be present in competitive athletes (P = 0.001) and in female athletes (P = 0.01). CONCLUSIONS: Our results showed that ventricular arrhythmias during exercise are more commonly associated with cardiovascular abnormalities in young competitive athletes and in female athletes. When present, they necessitate a thorough investigation and follow-up.

Circumferential and longitudinal strain in 3 myocardial layers in normal subjects and in patients with regional left ventricular dysfunction.

BACKGROUND: The left ventricle is not homogenous and is composed of 3 myocardial layers. Until recently, magnetic resonance imaging has been the only noninvasive technique for detailed evaluation of the left ventricular (LV) wall. The aim of this study was to analyze strain in 3 myocardial layers using speckle-tracking echocardiography. METHODS: Twenty normal subjects and 21 patients with LV dysfunction underwent echocardiography. Short-axis (for circumferential) and apical (for longitudinal strain) views were analyzed using modified speckle-tracking software enabling the analysis of strain in 3 myocardial layers. RESULTS: In normal subjects, longitudinal and circumferential strain was highest in the endocardium and lowest in the epicardium. Longitudinal endocardial and mid layer strain was highest in the apex and lowest in the base. Epicardial longitudinal strain was homogenous over the left ventricle. Circumferential 3-layer strain was highest in the apex and lowest in the base. In patients with LV dysfunction, strain was lower, with late diastolic or double peak. CONCLUSIONS: Three-layer analysis of circumferential and longitudinal strain using speckle-tracking imaging can be performed on a clinical basis and may become an important method for the assessment of real-time, quantitative global and regional LV function.

The usefulness of microvolt T-wave alternans in the risk stratification of patients with hypertrophic cardiomyopathy.

BACKGROUND: Patients with hypertrophic cardiomyopathy are prone to ventricular arrhythmias and sudden death. Identifying patients at risk of sudden death is difficult. OBJECTIVES: To determine whether microvolt T-wave alternans detected during exercise or rapid atrial pacing can identify patients with HCM who are at risk of ventricular arrhythmias and sudden death. METHODS: This prospective observational study included 21 patients with HCM: the disease was abstructive in 11, nonobstructive in 9 and apical in 1. TWA was measured while the patients were on anti-arrhythmic medication. RESULTS: TWA was positive in 9 patients (43%) and negative in 12 (57%). Three patients were resuscitated after sudden death before their enrollment in the study and two patients developed ventricular tachycardia and fibrillation respectively during the study period. After combining the endpoint of sudden death from a ventricular arrhythmia and the presence of ventricular arrhythmias on a Holter monitor, there was no significant correlation between the presence of a positive TWA and the presence of ventricular arrhythmias on the Holter monitor or a history of sudden death. CONCLUSION: TWA cannot be used as a non-invasive test for detecting patients with HCM and electrical instability. TWA is not useful for predicting sudden death in patients with HCM.

Outcome after implantation of cardioverter defibrillator [corrected] in patients with Brugada syndrome: a multicenter Israeli study (ISRABRU).

BACKGROUND: Many electrophysiologists recommend implantable cardioverter defibrillators for patients with Brugada syndrome who are cardiac arrest survivors or presumed at high risk of sudden death (patients with syncope or a familial history of sudden death or those with inducible ventricular fibrillation at electrophysiologic study). OBJECTIVES: To assess the efficacy and complications of ICD therapy in patients with Brugada syndrome. METHODS: The indications, efficacy and complications of ICD therapy in all patients with Brugada syndrome who underwent ICD implantation in 12 Israeli centers between 1994 and 2007 were analyzed. RESULTS: There were 59 patients (53 males, 89.8%) with a mean age of 44.1 years. At diagnosis 42 patients (71.2%) were symptomatic while 17 (28.8%) were asymptomatic. The indications for ICD implantation were: a history of cardiac arrest (n = 11, 18.6%), syncope (n = 31, 52.5%), inducible VF in asymptomatic patients (n = 14, 23.7%), and a family history of sudden death (n = 3, 0.5%). The overall inducibility rates of VF were 89.2% and 93.3% among the symptomatic and asymptomatic patients, respectively (P = NS). During a follow-up of 4-160 (45 +/- 35) months, all patients (except one who died from cancer) are alive. Five patients (8.4%), all with a history of cardiac arrest, had appropriate ICD discharge. Conversely, none of the patients without prior cardiac arrest had appropriate device therapy during a 39 +/- 30 month follow-up. Complications were encountered in 19 patients (32%). Inappropriate shocks occurred in 16 (27.1%) due to lead failure/dislodgment (n = 5), T wave oversensing (n = 2), device failure (n = 1), sinus tachycardia (n = 4), and supraventricular tachycardia (n = 4). One patient suffered a pneumothorax and another a brachial plexus injury during the implant procedure. One patient suffered a late (2 months) perforation of the right ventricle by the implanted lead. Eleven patients (18.6%) required a reintervention either for infection (n = 1) or lead problems (n = 10). Eight patients (13.5%) required psychiatric assistance due to complications related to the ICD (mostly inappropriate shocks in 7 patients). CONCLUSIONS: In this Israeli population with Brugada syndrome treated with ICD, appropriate device therapy was limited to cardiac arrest survivors while none of the other patients including those with syncope and/or inducible VF suffered an arrhythmic event. The overall complication rate was high.

Use of a combination of class III and class Ic antiarrhythmic agents in patients with electrical storm.

STUDY OBJECTIVE: To determine the efficacy of the combination of class III and class Ic antiarrhythmic agents in suppressing an electrical storm in patients with and without a transvenous implantable cardioverter-defibrillator (ICD). DESIGN: Retrospective medical record review. SETTING: Arrhythmia service of an academic medical center in Zerifin, Israel. PATIENTS: Ten patients who experienced an electrical storm that was not effectively treated with amiodarone or sotalol monotherapy between December 15, 1999, and June 13, 2007. MEASUREMENTS AND MAIN RESULTS: The medical records of 152 patients who received an ICD during the study period were reviewed. Twenty patients experienced an electrical storm, an arrhythmia defined as more than two episodes of hemodynamically unstable ventricular tachycardia during a 24- hour period. Ten of the 20 patients responded favorably to amiodarone or sotalol monotherapy (class III antiarrhythmics), but in 10 patients, the combination of a class III and a class Ic antiarrhythmic agent was needed to effectively eliminate the electrical storm. Of the 10 patients who required both agents, two (20%) developed an electrical storm before implantation of their ICD. In another patient who had ongoing ischemia, ventricular tachycardia recurred, but the drug combination decreased the number of ventricular arrhythmia episodes. One patient with dilated cardiomyopathy had one recurrence of ventricular tachycardia, which was terminated with antitachycardia pacing. Three patients died during a mean +/- SD follow-up of 8.7 +/- 9.9 months. CONCLUSION: Electrical storm can be acutely treated with the combination of a class III and a class Ic antiarrhythmic agent when a class III agent alone is insufficient and when radiofrequency ablation is not an option. Patients receiving this drug combination can be discharged from the hospital only if they have an ICD.

Real-time quantitative automatic assessment of left ventricular ejection fraction and regional wall motion by speckle imaging.

BACKGROUND: Echocardiographic assessment of left ventricular function includes calculation of ejection fraction and regional wall motion analysis. Recently, speckle imaging was introduced for quantification of left ventricular function. OBJECTIVES: To assess LVEF by speckle imaging and compare it with Simpson's method, and to assess the regional LV strain obtained by speckle imaging in relation to conventional echocardiographic scores. METHODS: Thirty consecutive patients, 28 with regional LV dysfunction, underwent standard echocardiographic evaluation. LV end-diastolic volume, LV end-systolic volume and EF were calculated independently by speckle imaging and Simpson's rule. The regional peak systolic strain presented by speckle imaging as a bull's-eye map was compared with the conventional visual estimate of echo score. RESULTS: Average EDV obtained by speckle imaging and by Simpson's method was 85.1 vs. 92.7 ml (P = 0.38), average ESV was 49.4 vs. 48.8 ml (P = 0.94), calculated EF was 43.9 vs. 50.5% (P = 0.08). The correlation rate with Simpson's rule was high: 0.92 for EDV, 0.96 for ESV, and 0.89 for EF. The peak systolic strain in two patients without wall motion abnormality was 17.3 +/- 4.7; in normal segments of patients with regional dysfunction, peak systolic strain (13.4 +/- 4.9) was significantly higher than in hypokinetic segments (10.5 +/- 4.5) (P < 0.000001). The strain in hypokinetic segments was significantly higher than in akinetic segments (6.2 +/- 3.6) (P < 0.000001). CONCLUSIONS: Speckle imaging can be successfully used for the assessment of LV volumes and EF. Bull's-eye strain map, created by speckle imaging, can achieve an accurate real-time segmental wall motion analysis.