Israel Medical Association Journal

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: Atrial fibrillation (AF) is the most common arrhythmia in adults and is associated with increased mortality and morbidity.

Objectives: To characterize patients diagnosed with AF in primary care clinics in southern Israel.

Methods: We conducted a cross-sectional study in 14 primary care clinics of the largest health insurance fund in Israel, reviewing the electronic medical records of adults aged ≥ 25 years diagnosed with AF. The prevalence, evaluation, antithrombotic treatment and treatments for rate control/rhythm control were analyzed.

Results: We retrieved the records of 995 patients with a diagnosis of AF; the prevalence of AF was 1.5% (2.5% aged ≥ 45 years). The patients’ mean age was 73.5 ± 1.4 years and 55.3% were female. Vitamin K antagonist (VKA) was prescribed for 591 patients (59%), of whom 8.5% had no international normalized ratio follow-up tests for at least 3 months before our review. Among patients in the VKA treatment group the risk for thromboembolic events was considered to be high, moderate and low in 22% (n=131), 66% (n=391) and 12% (n=69), respectively. Patients with a low Congestive Hypertension Age Diabetes Stroke (CHADS2) score (odds ratio = 0.555, 95% confidence interval 0.357–0.862) and patients who did not receive VKA (OR[1] = 0.601, 95% CI[2] 0.459–0.787) received significantly less rate-control treatment. Of the patients with a low CHADS2 score (< 1) 52.7% received VKA treatment, and 39.4% with a high CHADS2 score (≥ 3) did not receive VKA. A positive correlation between anticoagulation and rate or rhythm control was found.

Conclusions: The prevalence and age distribution of AF in southern Israel are similar to findings in the western world. Many of the patients did not receive appropriate antithrombotic prophylaxis.

Background: As the lowest natural site on earth (-415 meters), the Dead Sea is unique for its high pressure and oxygen tension in addition to the unparalleled combination of natural resources. Furthermore, its balneotherapeutic resorts have been reported to be beneficial for patients with various chronic diseases.

Objectives: To evaluate the safety, quality of life (QoL), exercise capacity, heart failure, and arrhythmia parameters in patients with systolic congestive heart failure (SCHF) and implantable cardioverter defibrillator (ICD) following descent and stay at the Dead Sea.

Methods: The study group comprised patients with SCHF, New York Heart Association functional class II-III after ICD implantation. The following parameters were tested at sea level one week prior to the descent, during a 4 day stay at the Dead Sea, and one week after return: blood pressure, O₂ saturation, ejection fraction (echocardiography), weight, B-type natriuretic peptide (BNP), arrhythmias, heart rate, heart rate variability (HRV), and QoL assessed by the Minnesota Living with Heart Failure questionnaire.

Results: We evaluated 19 patients, age 65.3 ± 9.6 years, of whom 16 (84%) were males and 18 (95%) had ICD-cardiac resynchronization therapy. The trip to and from and the stay at the Dead Sea were uneventful and well tolerated. The QoL score improved by 11 points, and the 6 minute walk increased by 63 meters (P < 0.001). BNP levels slightly increased with no statistical significance. The HRV decreased (P = 0.018). There were no significant changes in blood pressure, weight, O₂ saturation or ejection fraction.

Conclusions: Descent to, ascent from, and stay at the Dead Sea resort are safe and might be beneficial in some aspects for patients with sCHF and an ICD.
 

Background: Heart rate variability is a sensitive marker of cardiac sympathetic activity.

Objectives: To determine whether long-term hyperthyroidism induced by thyroxine suppressive therapy affects HRV[1].

Methods: Nineteen patients treated with suppressive doses of thyroxin for thyroid cancer and 19 age-matched controls were enrolled. Thyroid function tests and 1 minute HRV were performed on all subjects and the results were compared between the groups. The 1 minute HRV was analyzed during deep breathing and defined as the difference in beats/minute between the shortest and the longest heart rate interval measured by eletrocardiographic recording during six cycles of deep breathing.

Results:  One minute HRV during deep breathing was significantly lower among thyroxine-treated patients compared to healthy controls (25.6 ± 10.5 vs. 34.3 ± 12.6 beats/min, P < 0.05). There were no significant differences in mean, maximal and minimal heart rate between the groups

Conclusions: Thyroxine therapy administered for epithelial thyroid cancer resulted in subclinical hyperthyroidism and significantly decreased HRV due to autonomic dysfunction rather than basic elevated heart rate.

Background: Syncope is a common clinical problem that often remains undiagnosed despite extensive and expensive diagnostic evaluation.

Objectives: To assess the diagnostic evaluation, costs and prognosis of patients hospitalized for syncope in a tertiary referral center according to discharge diagnosis.

Methods: We retrospectively reviewed the medical records of patients with a diagnosis of syncope discharged from a tertiary referral center in 1999. In addition, mortality data were obtained retrospectively a year after discharge for each patient.

Results: The study group comprised 376 patients. Discharge etiologies were as follows: vasovagal 26.6%, cardiac 17.3%, neurological 4.3%, metabolic 0.5%, unexplained 47.3%, and other 4%. A total of 345 patients were admitted to the internal medicine department, 28 to the intensive cardiac care unit, and 3 to the neurology department. Cardiac and neurological tests were performed more often than other tests, with a higher yield in patients with cardiac and neurological etiologies respectively. The mean evaluation cost was 11,210 ± 8133 shekels, and was higher in the ICCU[1] than in internal medicine wards (19,210 ± 11,855 vs. 10,443 ± 7314 shekels, respectively; P = 0.0015). Mean in-hospital stay was 4.9 ± 4.2 days, which was longer in the ICCU than in medicine wards (7.2 ± 5.6 vs. 4.6 ± 3.5 days, respectively; P = 0.024). Short-term mortality rates (30 days after discharge) and long-term mortality rates (1 year after discharge) were 1.9% and 8.8% respectively, and differed according to discharge etiology. LTM[2] rates were significantly higher in patients discharged with cardiac, neurological and unknown etiologies (not for vasovagal), compared with the general population of Israel (1 year mortality rate for the age-adjusted [65 years] general population = 2.2%). The LTM rate was higher in patients discharged with a cardiac etiology than in those with a non-cardiac etiology (15.4% vs. 7.4%, P = 0.04). Higher short and long-term mortality rates were associated with higher evaluation costs.

Conclusions: Hospitalization in a tertiary referral center for syncope is associated with increased mortality for most etiologies (except vasovagal), cardiac more than non-cardiac. Despite high costs of inpatient evaluation, associated with more diagnostic tests, longer in-hospital stay and higher mortality rates, nearly half of the patients were discharged undiagnosed. Outpatient evaluation should be considered when medically possible.

Background: Previous studies have documented an increased incidence of cardiac mortality and sudden death during winter months.

Objectives: To evaluate seasonal variation in sudden death in a hot climate such as the desert region of southern Israel.

Methods: We analyzed the files of 243 consecutive patients treated for out-of-hospital sudden death by the Beer Sheva Mobile Intensive Care Unit during 1989-90. Daily, monthly and seasonal incidence of sudden death was correlated with meteorological data, including temperature, heat stress, relative humidity and barometric pressure.

Results: The seasonal distribution of sudden death was 23% in spring, 21% in summer, 25% in autumn and 31% in winter (not significant). In patients with known heart disease there were more episodes of sudden death in cold weather (<15.4°C) than hot (>34.2°C) (16 vs. 3, P<0.05). Resuscitation was less successful in cold compared with hot weather (28 vs. 11, P<0.05). Of patients older than 65 years, 11 sustained sudden death when heat stress was below 12.4°C compared to 2 patients when heat stress was above 27.5°C (P=0.05).

Conclusion: Despite the warm desert climate, there were more cases of sudden death in older patients and in those with known heart disease during the winter season and on particularly cold days.