Israel Medical Association Journal

Recognizing myocarditis is a diagnostic and therapeutic challenge due to the heterogeneity of its clinical presentation and the wide range of etiologies. There is a lack of uniformity among position papers and guidelines from various professional societies regarding the definition and diagnostic workout, including recommendations for performing endomyocardial biopsy (EMB) and medical management, especially the use of immunosuppressive regimens [1-3]. Moreover, there is significant variability among medical centers in Israel in the diagnostic and therapeutic approaches to acute myocarditis. The purpose of this position paper is to present ways to standardize the management of acute myocarditis in Israel [4] by providing up-to-date definitions of the clinical categories of myocarditis, diagnostic criteria, and therapeutic approaches that correspond to the realities of our healthcare system.

In the position statement on the definition and diagnosis of acute myocarditis on page XXX of this issue of the Israel Medical Association Journal (IMAJ), we discussed contemporary criteria for definition of acute myocarditis and inflammatory cardiomyopathy [1-6]. We also addressed current diagnostic methods including indications for endomyocardial biopsy (EMB) [7-21]. In this position statement, we discuss the management approaches during hospitalization and following hospital discharge, including specific forms of myocarditis and recommendations for returning to physical activity after myocarditis [21-36].

Background: Cannabis consumption is suspected of causing arrhythmias and potentially sudden death.

Objectives: To investigate prevalence and temporal relationships between cannabis use and onset of symptomatic arrhythmias among cancer patients using Belong.life, a digital patient powered network application.

Methods: Real-world data (RWD) were obtained through Belong.Life, a mobile application for cancer patients who use cannabis routinely. Patients replied anonymously and voluntarily to a survey describing their demographics, medical history, and cannabis use.

Results: In total, 354 cancer patients (77% female, 71% 50–69 years of age) replied: 33% were smokers and 49% had no co-morbidities. Fifteen had history of arrhythmias and two had a pacemaker; 64% started cannabis before or during chemotherapy and 18% had no chemotherapy. Cannabis indication was symptom relief in most patients. The mode of administration included oil, smoking, or edibles; only 35% were prescribed by a doctor. Cannabis type was delta 9-tetrahydrocannabinol > 15% in 43% and cannabidiol in 31%. After starting cannabis, 24 patients (7%) experienced palpitations; 13 received anti-arrhythmic drugs and 6 received anticoagulation. Eleven needed further medical investigation. Three were hospitalized. One had an ablation after starting cannabis and one stopped cannabis due to palpitations. Seven patients (2%) reported brady-arrhythmias after starting cannabis, but none needed pacemaker implantation.

Conclusions: RWD showed that in cancer patients using cannabis, the rate of reported symptomatic tachy- and brady-arrhythmias was significant (9%) but rarely led to invasive treatments. Although direct causality cannot be proven, temporal relationship between drug use and onset of symptoms suggests a strong association.

Background: The incidence, characteristics, and clinical significance of catheter-induced mechanical suppression (trauma) of ventricular arrhythmias originating in the outflow tract (OT) area have not been thoroughly evaluated.

Objectives: To determine these variables among our patient cohort.

Methods: All consecutive patients with right ventricular OT (RVOT) and left ventricular OT (LVOT) arrhythmias ablated at two medical centers from 1998 to 2014 were included. Patients were observed for catheter-induced trauma during ablation procedures. Procedural characteristics, as well as response to catheter-induced trauma and long term follow-up, were recorded.

Results: During 288 ablations of OT arrhythmias in 273 patients (RVOT n=238, LVOT n=50), we identified 8 RVOT cases (3.3%) and 1 LVOT (2%) case with catheter-induced trauma. Four cases of trauma were managed by immediate radiofrequency ablation (RFA), three were ablated after arrhythmia recurrence within a few minutes, and two were ablated after > 30 minutes without arrhythmia recurrence. Patients with catheter-induced trauma had higher rates of repeat ablations compared to patients without: 3/9 (33%) vs. 12/264 (0.45%), P = 0.009. The three patients with arrhythmia recurrence were managed differently during the first ablation procedure (immediate RFA, RFA following early recurrence, and delayed RFA). During the repeat procedure of these three patients, no catheter trauma occurred in two, and in one no arrhythmia was observed.

Conclusions: Significant catheter-induced trauma occurred in 3.1% of OT arrhythmias ablations, both at the RVOT and LVOT. Arrhythmia suppression may last > 30 minutes and may interfere with procedural success. The optimal mode of management following trauma is undetermined.

Background: Left ventricular outflow tract (LVOT) arrhythmias are increasingly recognized. Data regarding the distribution of the sites of origin (SOO) of the arrhythmias are sparse.

Objectives: To describe the clinical characteristics of patients with LVOT arrhythmias and the distribution of their SOO. 

Methods: All 42 consecutive patients with LVOT arrhythmias who underwent radiofrequency (RF) ablation during the period 2000–2014 were included. SOO identification was based on mapping activation, pace mapping and a 3D mapping system in eight patients. 

Results: The study group comprised 28 males (66.7%) and 14 females, the mean age was 55 ±15.4 years. Most patients (76%) were symptomatic. All suffered from high grade ventricular arrhythmias. Left ventricular (LV) dysfunction (ejection fraction ≤ 50%) was observed in 15 patients (35.7%), of whom 14 (93.3%) were males. The left coronary cusp (LCC) was the most common arrhythmia SOO (64.3%). Other locations were the right coronary cusp (RCC), the junction of the RCC-LCC commissure, aortic-mitral continuity, endocardial-LVOT, and a coronary sinus branch. Acute successful ablation was achieved in 29 patients (69%) and transient arrhythmia abolition in 40 (95.2%). There was a trend for a higher success rate using cooled tip ablation catheters as compared to standard catheters. The ablation procedure significantly improved LV function in all patients with tachycardiomyopathy. 

Conclusions: LVOT arrhythmias mostly originate from the LCC and are associated with LV dysfunction in 36% of patients. Knowledge regarding the prevalence of the anatomic origin of the LVOT arrhythmias may help achieve successful ablation. The use of cooled tip ablation catheters might have beneficial effects on the success rate of the procedure.

 

Objectives: To investigate the results of PVS after MI, according to date of completion.

Methods: PVS results were interpreted according to the mode of MI management in 801 asymptomatic patients: 301 (group I) during the period 1982–1989, 315 (group II) during 1990–1999, and 185 (group III) during 2000–2010. The periods were chosen based on changes in MI management. Angiotensin-converting enzyme (ACE) inhibitors had been given since 1990; primary angioplasty was performed routinely since 2000. The PVS protocol was the same throughout the whole study period.

Results: Group III was older (61 ± 11 years) than groups I (56 ± 11) and II (58 ± 11) (P < 0.002). Left ventricular ejection fraction (LVEF) was lower in group III (36.5 ± 11%) than in groups I (44 ± 15) and II (41 ± 12) (P < 0.000). Monomorphic VT < 270 beats/min was induced as frequently in group III (28%) as in group II (22.5%) but more frequently than in group I (20%) (P < 0.03). Ventricular fibrillation and flutter (VF) was induced less frequently in group III (14%) than in groups I (28%) (P < 0.0004) and II (30%) (P < 0.0000). Low left ventricular ejection fraction (LVEF) and date of inclusion (before/after 2000) were predictors of VT or VF induction on multivariate analysis.

Conclusions: Induction of non-specific arrhythmias (ventricular flutter and fibrillation) was less frequent than before 2000, despite the indication of PVS in patients with lower LVEF. This decrease could be due to the increased use of systematic primary angioplasty for MI since 2000. 

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 of athletes 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 ≥ 3 ventricular premature beats (VPB) (group A) and 102 athletes had ventricular couplets or non-sustained ventricular tachycardia (NSVT) during an exercise test (group B). A control group of 92 athletes without ventricular arrhythmias was randomly selected from the database (group C). Of the 192 athletes 39 returned 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 from group 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 initial exercise test than in the follow-up test (P = 0.021). Most of the athletes who had VPB and/or ventricular 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. 

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.
 

Telemedicine is the application of advanced telecommunication technology for diagnostic, monitoring and therapeutic purposes. It enables data transmission from the patient's whereabouts or his/her primary care provider to a specialized medical call center. Telecardiology is a highly developed medical discipline involving almost every aspect of cardiology, including acute coronary syndromes, arrhythmias, congestive heart failure, sudden cardiac arrest and others. Israel is one of the leading countries in the use of telecardiology, achieving both extended survival, improvement of the patient's quality of life, and significant reduction in health costs. 

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: Catheter ablation is assuming a larger role in the management of patients with cardiac arrhythmias. Conventional fluoroscopic catheter mapping has limited spatial resolution and involves prolonged fluoroscopy. The non-fluoroscopic electroanatomic mapping technique (CARTO) has been developed to overcome these drawbacks.

Objectives: To report the early and late outcome in patients with different arrhythmias treated with radiofrequency ablation combined with the CARTO mapping and navigation system.

Methods: The study cohort comprised 125 consecutive patients with different cardiac arrhythmia referred to our center from January 1999 to July 2005 for mapping and/or ablation procedures using the CARTO system. Forty patients (32%) had previous failed conventional ablation or mapping procedures and were referred by other centers. The arrhythmia included atrial fibrillation (n=13), atrial flutter (n=38), atrial tachycardia (n=25), ventricular tachycardia (n=24), arrhythmogenic right ventricular dysplasia (n=9), and supraventricular tachycardia (n=16).

Results: During the study period, a total of 125 patients (mean age 49 ± 19 years, 59% males) underwent electrophysiological study and electroanatomic mapping of the heart chambers. Supraventricular arrhythmias were identified in 92 patients (73 %) and ventricular arrhythmias in 33 (27%). Acute and late success rates, defined as termination of the arrhythmia without anti-arrhythmic drugs, were 87% and 76% respectively. One patient (0.8%) developed a clinically significant complication.

Conclusions: The CARTO system advances our understanding of arrhythmias, and increases the safety, efficacy and efficiency of radiofrequency ablation.

Background: The significance of arrhythmia occurring after successful recanalization of an occluded artery during treatment following primary percutaneous coronary intervention for ST-segment elevation myocardial infarction is controversial.

Objectives: To study the association of reperfusion arrhythmia with short and long-term survival.

Methods: We used a prospective registry of consecutive STEMI[1] patients undergoing PPCI[2]. Patients with an impaired epicardial flow (TIMI flow grade < 3) at the end of the procedure were excluded.

Results: Of the 688 patients in the study group, 22% were women. Mean (± SD) age of the cohort was 61 (± 14) years and frequent co-morbidities included diabetes mellitus (25%), dyslipidemia (55%), hypertension (43%) and smoking (41%). RA[3] was recorded in 200 patients (29%). Patients with RA had lower rates of diabetes (16% vs. 30%, P < 0.01) and hypertension (48% vs. 62%, P < 0.01), and a shorter median pain-to-balloon time (201 vs. 234 minutes, P < 0.01) than patients without RA. Thirty day mortality was 3.7% and 8.3% for patients with and without RA, respectively (P = 0.04). After controlling for age, gender and pain-to-balloon time the hazard ratio for mortality for patients with RA during a median follow-up period of 466 days was 0.46 (95% confidence interval 0.23–0.92).

Conclusions: The occurrence of RA immediately following PPCI for acute STEMI is associated with better clinical characteristics and identifies a subgroup with a particularly favorable prognosis.