The present study was undertaken to test the hypothesis that the human RR-QT relationship during dynamic exercise differs markedly from that during the recovery phase. Fourteen subjects from the age of 16 to 71 years exercised on a treadmill according to the Bruce protocol. Electrocardiograms were recorded continuously on a magnetic tape, from 1 minute before exercise to 10 minutes into recovery. An exponential formula, proposed by us earlier, closely represented the exercise RR-QT data. However, it was not appropriate for the often S-shaped recovery curves which invariably deviated from the exercise curves, exhibiting hysteresis. Initially, all recovery QT intervals were shorter than the exercise values, but later in the recovery, some crossed the exercise curves from below, resulting in longer QT intervals. The recovery data were fitted by a third degree polynomial, and the hysteresis was calculated as the area between the exercise and recovery curves within a 150 ms range of the RR interval starting from its minimum value. The mechanisms for the occurrence of hysteresis are likely to involve the sympatho-adrenal activity in the early post-exercise period and the time course of QT interval adaptation to rapid changes in the RR interval.

Sleep apnea is very common in patients with cardiovascular disease, especially in patients with hypertension. Over the last few decades a number of discoveries have helped support a causal relationship between the two and even resistant hypertension. The role neurogenic mechanisms play has gathered more attention in the recent past due to their immediate bedside utility. Several innovative discoveries in pathogenesis including those exploring the role of baroreflex gain, cardiovascular variability, chemoreceptor reflex activation and the sympathetic nervous system have emerged. In this review, we discuss the epidemiology of sleep apnea and hypertension and the pathogenic mechanisms contributing to neurogenic hypertension. Furthermore, recent management strategies in addition to continuous positive airway pressure (CPAP), such as upper airway stimulation and renal denervation that target these pathogenic mechanisms, are also discussed.

Background and study aims Esophagogastroduodenoscopy (EGD), the most common method used for diagnosing upper gastrointestinal diseases, is often limited by the presence of foam and mucous. Thus, this study was designed to detect whether the combination of simethicone with N-acetyl cysteine (NAC) as premedication before EGD improves mucosal visualization. Patients and methods A total of 768 consenting patients were enrolled in this prospective, double-blind, randomized placebo-controlled trial in four groups (A: simethicone + N-acetyl cysteine; B: simethicone alone; C: NAC alone; and D: placebo). After 20 minutes of consuming the corresponding solution, EGD was done and multiple images were obtained from the esophagus, stomach, and duodenum. Based on the various images obtained, the study parameters were calculated. Statistical Analysis Software (SAS) was used to analyze the results using Kruskal-Wallis with the Bonferroni correction method. Results The study population consisted of 57 % men and the mean age was 44.18 years. Each group was randomized with 192 participants. Group A (combination of simethicone + NAC) premedication had the lowest total mucosal visibility score of 8.31, a significantly lower score for mucous/bubbles obscuring the vision, and less time to complete the procedure. Also, 81 % of the participants in group A did not require flushing to clear the mucous/bubbles. There were no side effects due to this premedication in any of the groups. Conclusions  Using simethicone and NAC combined for premedication may improve the quality of EGD.

Fulminant myocarditis is characterized by life threatening heart failure presenting as cardiogenic shock requiring inotropic or mechanical circulatory support to maintain tissue perfusion. There are limited data on the role of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in the management of fulminant myocarditis. This review seeks to evaluate the management of fulminant myocarditis with a special emphasis on the role and outcomes with VA-ECMO use.

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