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.

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: 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.

 

Background: Familial dysautonomia is a hereditary disease characterized by dysfunction of the sensory and autonomic nervous systems. Studies in patients with familial dysautonomia have shown that abnormal cardiac autonomic denervation might influence repolarization. Autonomic tone also affects atrial conduction parameters and P-wave dispersion, which are predictive of atrial fibrillation.

Objectives: To examine the possible association of familial dysautonomia with abnormal atrial conduction and P-wave dispersion.

Methods: The study population included 12 patients with familial dysautonomia and age and sex-matched control subjects. All participants underwent a 12-lead electrocardiogram under strict conditions. P-wave lengths and P-wave dispersion were computed from a randomly selected beat and an averaged beat using designated computer software.

Results: There were no statistically significant differences between the groups in minimal, maximal, and average P-wave duration or P-wave dispersion for a randomly selected beat. P-wave dispersion for an averaged beat was also similar. During 6 months follow-up, no supraventricular arrhythmias were documented in either group.

Conclusions: We found that patients with familial dysautonomia had P-wave dispersion parameters not significantly different from those of controls. Further research is required to clarify the effects of dysautonomia on atrial conduction in familial dysautonomia.

Background: Long QT syndrome is an inherited cardiac disease, associated with malignant arrhythmias and sudden cardiac death.

Objectives: To map and identify the gene responsible for LQTS[1] in an Israeli family.

Methods: A large family was screened for LQTS after one of them was successfully resuscitated from ventricular fibrillation. The DNA was examined for suspicious loci by whole genome screening and the coding region of the LQT2 gene was sequenced.

Results: Nine family members, 6 males and 3 females, age (median and interquartile range) 26 years (13, 46), who were characterized by a unique T wave pattern were diagnosed as carrying the mutant gene. The LQTS-causing gene was mapped to chromosome 7 with the A614V mutation. All of the affected members in the family were correctly identified by electrocardiogram. Corrected QT duration was inversely associated with age in the affected family members and decreased with age.
Conclusions: Careful inspection of the ECG can correctly identify LQTS in some families. Genetic analysis is needed to confirm the diagnosis and enable the correct therapy in this disease

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.

Objective: To identify risk factors and associated conditions that may cause TdP[1] in patients on chronic amiodarone treatment.

Methods: We reviewed the data of six consecutive patients on chronic amiodarone treatment who were admitted to the intensive cardiac care unit due to syncope and TdP.

Results: The patients’ median age was 73.5 years, and five were women. Concomitantly, loratadine was given to two patients and trazodone to one patient. Associated and attributing conditions to the development of TdP were hypokalemia in three patients, drug-induced bradycardia in one and reduced left ventricular function in four.

Conclusions: TdP associated with chronic amiodarone treatment may occur when amiodarone is co-administered with drugs that may potentially prolong QT interval. Additional risk factors for amiodarone-associated TdP include female gender, hypokalemia, reduced left ventricular function and bradycardia.

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[1] TdP = torsade de pointes

Background: Anemia is a known risk factor for ischemic heart disease. Based on knowledge of the physiologic role of oxygen delivery to the myocardium, anemia may be a cause of more severe cardiovascular diseases or a marker of other processes occurring in the body that induce more severe disease.

Objectives: To investigate the relationship between anemia and the clinical picture of IHD[1], including manifestations, severity and complications.

Methods: The population studied comprised 417 similarly aged patients with IHD and anemia. The patients were categorized into subgroups of IHD according to disease severity: namely, angina pectoris, acute ischemia, acute myocardial infarction, congestive heart failure or cardiac arrhythmias. Two populations served as control groups: patients with anemia but no IHD (C-I) and patients with IHD without anemia (C-II). A standard anemia workup was conducted in all patients with IHD and anemia and a correlation was made between the hematologic parameters and the manifestations and complications of IHD.

Results: The common presenting symptom was chest pain in the study group and in C-II (94% and 86% respectively) and weakness (90%) in C-I. Patients with IHD and anemia tended to suffer from a more advanced degree of IHD (80%) compared to patients with IHD alone who had milder disease (46%). Hematologic values including hemoglobin, mean cell volume, serum iron and total iron binding capacity correlated inversely with disease severity among anemic patients with IHD. There were significant differences between the study group and C-II regarding CHF[2] (31% and 18% respectively) and arrhythmias (41% and 16% respectively). The mortality rate was higher in patients with IHD and anemia than in patients with IHD alone (13% and 4% respectively).

Conclusions: Anemia is a significant risk factor in IHD. It correlates with advanced IHD, CHF, rhythm disturbance and higher mortality rate. An aggressive therapeutic and preventive approach might improve the outcome of this disease.