Israel Medical Association Journal

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.

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 anticoagulant 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 admitted 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. 

 

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.

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 ≥ 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.
 

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[1] who are at risk of ventricular arrhythmias and sudden death.

Methods: This prospective observational study included 21 patients with HCM: 11 with hypertrophic obstructive cardiomyopathy, 9 with non-obstructive hypertrophic cardiomyopathy, and 1 with apical hypertrophic cardiomyopathy. TWA[2] 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 enrolment 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.

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[1] 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[2] obtained by speckle imaging and by Simpson’s method were 85.1 vs. 92.7 ml (P = 0.38), average ESV[3] 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.