RESUMEN
Objective: To compare heart rate variability in negative and positive responders to active phase of head-up tilt test
Study Design:Cross-sectional comparative study
Place and Duration of Study: Department of Cardiac Electrophysiology, Armed Forces Institute of Cardiology, Rawalpindi from Jan 2016 to Oct 2016
Material and Methods: Ninety three adult patients of either gender with recurrent unexplained syncope were recruited through convenience purposive sampling. The known cases of diabetes mellitus, cardiac diseases, cardiac arrhythmias and myocardial infarction were excluded from the study. Head-up tilt test was carried out on an electrically driven tilt table. DMS 300-4L Holters were used to obtain ambulatory ECG recordings during head-up tilt test. Cardio scan premier 12 lux software was used for analysis of heart rate variability frequency domain parameters
Results: Total ninety three patients of unexplained syncope were enrolled out of which, 77 [82.8 percent] patients responded positively and 16 [17.2 percent] patients gave a negative response. There was significant variation in heart rate variability frequency domain parameters being reduced in positive responders to active phase of head-up tilt test as compared to negative responders. This difference in mean values of heart rate variability frequency domain parameters between positive and negative responders was statistically significant with p-value less than 0.05
Conclusion: The heart rate variability frequency domain analysis done during initial 20 minutes of passive phase of head-up tilt test can predict the results of tests before the administration of drugs
RESUMEN
Background: Ventricular late potentials [VLPs] are low amplitude high frequency signals present in the terminal part of QRS complex detected by signal averaged ECG. They have emerged as robust tools for arrhythmia risk stratification in patients with cardiac diseases. Early detection of ventricular late potentials in patients with cardiomyopathy can help in risk stratification of ventricular arrhythmias leading to sudden cardiac death. The purpose of this study was to compare VLPs in patients with cardiomyopathy and healthy controls
Methods: The study was conducted in Department of Cardiac Electrophysiology, Armed Forces Institute of Cardiology, Rawalpindi. Sixty patients with cardiomyopathy [any type] along with 60 healthy controls were selected through non-probability purposive sampling. Patients meeting inclusion criteria were selected for Signal-Averaged ECG [SAECG]
Results: Ventricular late potentials were seen in 14 [23.3%] out of 60 patients with cardiomyopathy, while only 5 [8.3%] out of 60 healthy controls demonstrated ventricular late potentials. There was significant variation in frequency of patients with ventricular late potentials as compared to healthy controls [p=0.02]. The mean value of fQRS was 107.53+/-37.70 in cases while 80.32+/-24.19 in controls and the difference was statistically significant [p<0.001] while insignificant for RMS and LAS [p=0.52 and 0.87 respectively]
Conclusion: The frequency of patients with cardiomyopathy having ventricular late potentials is significantly higher compared to healthy controls
RESUMEN
Objective: To compare T wave alternans in patients with cardiomyopathy and healthy controls
Study Design: Cross-sectional comparative study
Place and Duration of Study: Department of Cardiac Electrophysiology, Armed Forces Institute of Cardiology Rawalpindi, from Feb 2016 to Aug 2016
Material and Methods: Sixty patients with cardiomyopathy [any type] along with sixty healthy controls of matched age and gender were recruited through non-probability purposive sampling. Patients with diabetes mellitus, cerebrovascular accident, heart failure, bundle branch block, systemic arterial hypertension and ongoing antiarrhythmic therapy were excluded from the study. DMS 300-4L Holters were used to obtain ambulatory ECG recordings. Cardio Scan premier 12 lux software was used for analysis of T wave alternans
Results: Total one twenty subjects were enrolled in the study. Cardiomyopathic patients with positive T wave alternans were 13 [21.7 %] out of 60, while only 4 [6.7%] out of 60 healthy controls demonstrated positive T wave alternans. There was significant variation in frequency of patients with positive T wave alternans as compared to healthy controls with p-value of 0.02. In cases the mean value of T wave alternans was 55.10 micro v +/- 33.58 while 39.45 micro v +/- 13.53 in controls. The difference in mean value of T wave alternans between cases and controls was significant with p-value of 0.001
Conclusion: The frequency of patients with cardiomyopathy having positive T wave alternans was significantly higher as compared to the healthy controls