Influence of Intermittent Fasting During Ramadan on Circadian Variation of Symptom-Onset and Prehospital Time Delay in Acute ST-Segment Elevation Myocardial Infarction.

Ramadan interferes with circadian rhythms mainly by disturbing the routine patterns of feeding and smoking. The objective of this study was to investigate the circadian pattern of ST elevation acute myocardial infarction (STEMI) during the month of Ramadan. We studied consecutive STEMI patients 1 month before and after Ramadan (non-Ramadan group-NRG) and during Ramadan (Ramadan group-RG). The RG group was also divided into two groups, based on whether they chose to fast: fasting (FG) and non-fasting group (NFG). The time of STEMI onset was compared. A total of 742 consecutive STEMI patients were classified into 4 groups by 6 h intervals according to time-of-day at symptom onset. No consistent circadian variation in the onset of STEMI was observed both between the RG (P = .938) and NRG (P = .766) or between the FG (P = .232) and NFG (P = .523). When analyzed for subgroups of the study sample, neither smoking nor diabetes showed circadian rhythm. There was a trend towards a delay from symptom onset to hospital presentation, particularly at evening hours in the RG compared with the control group. In conclusion, there was no significant difference in STEMI onset time, but the time from symptom onset to hospital admission was significantly delayed during Ramadan.

Serial echocardiographic changes with different body positions and sleeping side preference in heart failure patients.

BACKGROUND: The sleeping position plays an important role in overall health in both healthy individuals and heart failure (HF) patients, which complain of increasing dyspnea when adopting left lateral decubitus position (LLDP) that improves when turning over to the right lateral decubitus position (RLDP). Several theories have been proposed to explain this preference of HF patients; however, the underlying mechanisms remain unclear. METHOD: We evaluated consecutive dilated cardiomyopathy (DCMP) patients with regard to whether they had a sleeping position preference and analyzed early and late left ventricular filling velocities, tissue Doppler recordings, tricuspid annular plane systolic excursion (TAPSE), and left ventricular outflow tract time-velocity integral (LVOT-TVI). Baseline echocardiographic parameters were obtained first by LLDP, followed by the supine position (SP) and finally RLDP in each position for 10 minutes to ensure a stabilized hemodynamic milieu. RESULTS: A total of 26 DCMP patients were included in this study and a 78 echocardiographic examination performed. We detected that many HF patients preferred the right lateral decubitus sleeping position (RLDSP, 54%) and avoided from the left lateral decubitus sleeping position (LLDSP, 40%); the echocardiographic LVOT TVI and TAPSE parameters were statistically higher in RLDP compared to SP and LLDP. CONCLUSION: The echocardiographic LVOT TVI and TAPSE values as functional parameters of left and right ventricular function change with body position, and these hemodynamic changes may explain why HF patients willingly adopt RLDSP.

The short-term impact of the catheter ablation on noninvasive autonomic nervous system parameters in patients with paroxysmal atrial fibrillation.

BACKGROUND: The autonomic nervous system (ANS) is a potentially potent modulator of the initiation and perpetuation of atrial fibrillation (AF), whereas the presence of AF can activate and alter the ANS. The catheter ablation of AF (AFCA) may cause the cardiac ANS dysfunction, whereas restoration of sinus rhythm or sympathovagal imbalance by AFCA can reverse this process. Our principal goal was to investigate the short-term effect of AFCA on ANS functions evaluated by noninvasive chronotropic (CI), resting heart rate (RHR), and heart rate recovery (HRR) indices. METHOD: A total of 45 patients were enrolled with symptomatic, drug refractory paroxysmal AF undergoing first cryoballoon (CB) pulmonary vein antrum isolation (PVAI) with one 28-mm CB using single 3-minute freeze techniques without bonus applications. All patients underwent symptom-limited exercise treadmill testing to evaluate noninvasive parameters of ANS before PVAI. For those patients who remained in sinus rhythm, an additional exercise test was repeated after 1 and 3 months after discharge. RESULTS: The autonomic CI and RHR/HRR indices were impaired after PVAI and persisted post-PVAI 3 months. However, these parameters were not different in patients with and without recurrence. CONCLUSION: This study demonstrated that the successful AFCA might concurrently impair the ANS parameters. The autonomic imbalance between the sympathetic and parasympathetic activity after AFCA could either become antiarrhythmic and/or proarrhythmic based on which of the two components was going to prevail after successful AFCA. The impaired ANS balance after PVAI might also be another hypothetical mechanism for AF recurrence particularly in the absence of PV reconnection.

The Association between Whole Blood Viscosity and Coronary Collateral Circulation in Patients with Chronic Total Occlusion.

BACKGROUND AND OBJECTIVES: Coronary collateral circulation (CCC) has been attributed as inborn bypass mechanisms supporting ischemic myocardium. Various factors have been postulated in CCC. Whole blood viscosity (WBV) has been an underappreciated entity despite close relationships between multiple cardiovascular diseases. WBV can be calculated with a validated equation from hematocrit and total plasma protein levels for a low and high shear rate. On the grounds, we aimed to evaluate the association between WBV and CCC in patients with chronic total occlusion. SUBJECTS AND METHODS: A total of 371 patients diagnosed as having at least one major, chronic total occluded coronary artery were included. 197 patients with good CCC (Rentrop 2 and 3) composed the patient group. The poor collateral group consisted of 174 patients (Rentrop grade 0 and 1). RESULTS: Patients with poor CCC had higher WBV values for a low-shear rate (LSR) (69.5±8.7 vs. 60.1±9.8, p<0.001) and high-shear rate (HSR) (17.0±2.0 vs. 16.4±1.8, p<0.001) than the good collateral group. Correlation analysis demonstrated a significant negative correlation between the grade of CCC and WBV for LSR (ß=0.597, p<0.001) and HSR (ß=0.494, p<0.001). WBV for LSR (ß=0.476, p<0.001) and HSR (ß=0.407, p<0.001) had a significant correlation with the synergy between percutaneous coronary intervention with taxus and cardiac surgery (SYNTAX) score. A multivariate analysis showed that the WBV for both shear rates were independent risk factors of poor CCC (WBV at LSR, OR: 1.362 CI 95%: 1.095-1.741 p<0.001 and WBV at HSR, 1.251 CI 95%: 1.180-1.347 p<0.001). CONCLUSION: WBV has been demonstrated as the overlooked predictor of poor coronary collateralization. WBV seemed to be associated with microvascular perfusion and angiogenesis process impairing CCC development.