Israel Medical Association Journal

A 42-year-old healthy man collapsed suddenly in the street while walking. The patient received 2 minutes of basic life support until an automatic external defibrillator was brought and detected ventricular fibrillation (VF), which was successfully terminated by a single shock. The patient regained consciousness and was transferred to the hospital.

The patient’s physical examination was normal with no neurologic deficit. Blood pressure was 147/102 mmHg. Brain computed tomography showed normal findings. The first troponin I measurement within 1 hour of the event was in the normal range (19.6 ng/L, normal < 20 ng/L) and rose to 99.9 ng/L after 3 hours.

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.

Heart rate disorders and in particular sinus arrhythmias are known to accompany viral infections. Sinus tachycardia is prevalent in the presence of increased body temperature and respiratory rate. However, bradycardia has also been described for centuries to complicate viral illnesses

Background: The diagnosis of atrial fibrillation (AFIB) related cardiomyopathy relies on ruling out other causes for heart failure and on recovery of left ventricular (LV) function following return to sinus rhythm (SR). The pathophysiology underlying this pathology is multifactorial and not as completely known as the factors associated with functional recovery following the restoration of SR.

Objectives: To identify clinical and echocardiographic factors associated with LV systolic function improvement following electrical cardioversion (CV) or after catheter ablation in patients with reduced ejection fraction (EF) related to AFIB and normal LV function at baseline.

Methods: The study included patients with preserved EF at baseline while in SR whose LVEF had reduced while in AFIB and improved LVEF following CV. We compared patients who had improved LVEF to normal baseline to those who did not.

Results: Eighty-six patients with AFIB had evidence of reduced LV systolic function and improved EF following return to SR. Fifty-five (64%) returned their EF to baseline. Patients with a history of ischemic heart disease (IHD), worse LV function, and larger LV size during AFIB were less likely to return to normal LV function. Multivariant analysis revealed that younger patients with slower ventricular response, a history of IHD, larger LV size, and more significant deterioration of LVEF during AFIB were less likely to recover their EF to baseline values.

Conclusions: Patients with worse LV function and larger left ventricle during AFIB are less likely to return their baseline LV function following the restoration of sinus rhythm.

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: Multiform fascicular tachycardia (FT) was recently described as a ventricular tachycardia (VT) that has a reentrant mechanism using multiple fascicular branches and produces alternate fascicular VT forms. Ablating the respective fascicle may cause a change in the reentrant circuit resulting in a change in morphology. Ablation of the septal fascicle is crucial for successful treatment.

Objectives: To describe four cases of FT in which ablation induced a change in QRS morphologies and aggravated clinical course.

Methods: Four out of 57 consecutive FT cases at three institutions were retrospectively analyzed and found to involve multiform FT. These cases underwent electrophysiological study, fascicular potential mapping, and electroanatomical mapping. All patients initially had FT with right bundle branch block (RBBB) and superior axis morphology.

Results: Radiofrequency catheter ablation (RFCA) targeting the distal left posterior fascicle (LPF) resulted in a second VT with an RBBB-inferior axis morphology that sometimes became faster and/or incessant and/or verapamil-refractory in characteristics. RFCA in the upper septum abolished the second VT with no complications and uneventful long-term follow-up.

Conclusions: The change in FT morphology during ablation may be associated with a change in clinical course when shifting from one route to another and may aggravate symptoms. Targeting of the proximal conduction system (such as bifurcation, LPF, left anterior fascicle, high septal/auxiliary pathway) may serve to solve this problem.

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.