Comparison of heart rate variability and cardiac arrhythmias in polluted and clean air episodes in healthy individuals.

OBJECTIVE: Pathophysiological mechanisms and pathways linking cardiovascular mortality and morbidity with air pollution were recently hypothesized. The present study evaluated association between air pollution and changes in heart rate variability as a marker of cardiac autonomic function in healthy individuals, and also determined the frequency of cardiac arrhythmias and QT interval changes on polluted compared to unpolluted days. METHODS: Continuous Holter electrocardiography (ECG) monitoring was conducted on 21 young healthy individuals in the two episodes of clean air and elevated air pollution in Tehran. All subjects underwent a medical history review, a physical examination and echocardiography in order to rule out structural heart diseases. Measured pollutants and parameters included NO(2), CO(2), O(3), SO(2), and PM10, which all showed significantly higher concentrations on polluted days. Holter parameters were measured for 24-h time segments and compared. RESULTS: Maximum heart rate was significantly lower in polluted air conditions in comparison with clean air conditions (115.1 ± 32.2 vs. 128.9 ± 17.7), and the square root of the mean of squared differences between adjacent NN intervals (r-MSSD) was higher in polluted air compared to clean air (99.0 ± 58.2 vs. 58.5 ± 26.4). Also, the occurrence of nonsustained supraventricular tachycardia was reported in 42.9% of participants in air pollution episodes, whereas this arrhythmia was not seen in clear air conditions (p = 0.001). CONCLUSION: Changes in air pollution indices may lead to the occurrence of nonsustained supraventricular tachycardia, a slight reduction in maximum heart rate, and an increase in r-MSSD in healthy individuals. Air quality monitoring in cities associated with a high exposure to air pollutants is recommended in order to prevent such events.

High accuracy of myocardial perfusion imaging in patients with left bundle branch block: comparison of four interpretation approaches.

Although myocardial perfusion imaging (MPI) with pharmacologic stress is the standard method for screening coronary artery disease (CAD) in patients with left bundle branch block (LBBB), controversies remain about its correct interpretation. We sought the best interpretation approach in these patients to achieve higher accuracy. Forty-two patients with LBBB underwent MPI with dipyridamole stress and the criteria for positive results with four patterns of interpretation were as follows: Pattern A: any reversible or irreversible perfusion abnormality in the myocardium irrespective of the location or extension was considered positive. Pattern B: any reversible or irreversible perfusion abnormalities except in the septal/anteroseptal region were defined as positive. Pattern C: in the absence of fixed LV cavity dilatation, the scan was interpreted the same as pattern A, while in the presence of fixed LV cavity dilatation, only the abnormalities outside the LAD territory was defined as positive. Pattern D: as in pattern C, except that in the absence of fixed LV cavity dilatation, the scan was read according to pattern B. For all patients, the angiographic results were considered as gold standard of CAD diagnosis. Our results showed that the false positive rate of MPI in patients with fixed LV dilatation was 50%, while in cases with normal LV size or transient dilatation, was 38.5%. This difference was more prominent in the female patients. The accuracy for screening CAD for patterns A, B, C and D were 57%, 62%, 69% and 69%, respectively. Pattern D was the better approach in female cases and patients with fixed septal/anteroseptal defects. In conclusion, a) in the male population without fixed defects in the septal/anteroseptal region, the specificity and accuracy are high in all patterns and the pattern of reading does not significantly influence the diagnostic value of MPI for CAD screening. b) in LBBB patients, fixed defects limited to the septal/anteroseptal region should be considered a significant finding only when LV cavity is not dilated.

Ablation of focal right upper pulmonary vein tachycardia using retrograde aortic approach.

The use of diagnostic and therapeutic methods for assessing pulmonary vein due to its status as a main source of ectopic beats for the initiation of atrial dysrrythmias is strongly recommended. We report the case of a 13-year-old girl who was admitted to our hospital with the electrocardiogram manifestation of an ectopic atrial tachycardia. The focus of arrhythmia was inside the right upper pulmonary vein. The patient underwent successful ablation with a conventional electrophysiology catheter via the retrograde aortic approach. We showed that when the origin of atrial tachycardia is in the right upper pulmonary vein, it is possible to advance the catheter into this vein via the retrograde aortic approach and find the focus of arrhythmia. This case demonstrates that right upper pulmonary vein mapping is feasible through the retrograde aortic approach and it is also possible to ablate the arrhythmia using the same catheter and approach.

Association between Androgenic Hormone Levels and Left Ventricular Ejection Fraction.

BACKGROUND: Androgens have been shown to have diverse effects on the cardiovascular system. The aim of this study was to compare androgenic hormone levels in patients with different left ventricular ejection fractions (EF). METHODS: The study population consisted of 515 consecutive men who were referred for angiographic studies and whose results of echocardiography and coronary angiography were available. The patients were classified into four groups: EF < 35%, EF = 35-45%, EF = 45-54%, and EF ≥ 55% to evaluate the trends of baseline characteristics and serum androgens, including free testosterone (fT), total testosterone (tT), and dehydroepiandrosterone sulfate (DHEAS). To better elucidate the difference in the patients with severe heart failure, the patients were divided into two groups according to their EF level, and comparisons were repeated between those with EF < 35% and the ones with EF ≥ 35%. RESULTS: There were statistically significant trends in some characteristics in the patients with different levels of EF. The subjects with higher EF levels were less likely to have diabetes (p value < 0.001), coronary artery lesion (p value < 0.001), or high levels of C-reactive protein (CRP) (p value < 0.001). As regards the patients with severe heart failure, our regression analysis revealed that the fT level was significantly lower in those with EF < 35% than in the ones with EF ≥ 35% (5.82 ± 2.73 pg/mL vs. 6.88 ± 3.34 pg/mL, p value < 0.05). CONCLUSION: A significant association was found between the level of fT and EF < 35%. There is a need for further controlled prospective studies to delineate any possible causal relationship accurately.

New technique: repositioning of dislodged atrial pacing lead with a specially designed urological basket.

The rate of dislodgement of atrial pacing leads is approximately 3%. To solve this problem, reoperation and repositioning of these leads is one of the solutions. Some operators have reported repositioning these leads with snare systems or deflectable catheters. In this communication, we present a new method using a specially designed urological basket to solve this problem.