Witold Orszulak

QT/RR relationship in patients after remote anterior myocardial infarction with left ventricular dysfunction and different types of ventricular arrhythmias.

Background: QT/RR relationship was found to be both rate‐dependent and rate‐independent, what suggests the influence of autonomic drive and other not‐autonomic related factors on it. The steeper QT/RR slope in patients after acute myocardial infarction (MI) was described, but the relationship to ventricular arrhythmias is unknown. The purpose of this study was to calculate differences in QT/RR relationship in patients after remote anterior MI with left ventricular dysfunction and different types of ventricular arrhythmias.

Heart Rate Variability: Its Association with Hemodynamic Function of the Left Ventricle in Patients with Coronary Heart Disease

Patients with heart failure secondary to coronary heart disease (CHD) are characterized by an imbalance of the autonomic nervous system, which can be assessed by analysis of the heart rate variability (HRV). However it is still unclear whether all patients with CHD reveal suppression of HRV and if it is related to hemodynamic function and contractile disturbances of the left ventricle. To answer these questions data from 105 consecutive patients were analyzed and compared with 17 healthy subjects. All study participants underwent 24‐hour ambulatory ECG recordings with calculation of HRV parameters and angiographic examination after collection of clinical data and other noninvasive evaluations. Time‐ (SDRR, SDANN, SD, pNN50) and frequency‐ (LF, HF) domain parameters of HRV were assessed. All ventriculographic and hemodynamic measurements were used in the analysis. Highly significant correlations were found between all HRV parameters, and left ventricular ejection fraction (LVEF) and left ventricular end‐diastolic pressure (P < 0.001). Patients with LVEF < 40% were characterized by significantly lower values of HRV and impairment or lack (LVEF < 20%) of diurnal variation of frequency‐domain measurements of HRV. Patients with segmental akinesis or dyskinesis also had lower values of HRV. The group with dyskinesis was characterized by significantly lower diurnal rhythms of LF and HF, independent of LVEF.

Impact of left ventricular remodeling on ventricular repolarization and heart rate variability in patients after myocardial infarction treated with primary PCI: prospective 6 months follow-up.

Background: The relation between postinfarction left ventricle remodeling (LVR), autonomic nervous system and repolarization process is unclear. Purpose of the study was to assess the influence of LVR on the early (QTpeak) and late (TpeakTend) repolarization periods in patients after myocardial infarction (MI) treated with primary PCI. The day‐to‐night differences of repolarization parameters and the relation between QT and heart rate variability (HRV) indices, as well left ventricle function were also assessed.

Heart rate turbulence in postinfarction patients with history of malignant ventricular arrhythmias

UNLABELLED In the study, there has been retrospectively analyzed heart rate turbulence in postinfarction patients. The cohort of 158 patients consisted of 94 patients with documented ventricular tachycardia and/or ventricular fibrillation (VT/VF) and 64 patients without history of VT/VF. Turbulence onset and slope were calculated from Holter recordings, and left ventricle ejection fraction (LVEF) ≤35% was regarded as severe left ventricle dysfunction. Study groups were similar in age and sex. Left ventricle ejection fraction was lower in the VT/VF group (P < .005). Patients with VT/VF had higher turbulence onset (-0.22% ± 1% vs -0.8% ± 2%; P = .005) and lower turbulence slope (2.6 ± 1.9 vs 4.1 ± 3.5 milliseconds per RR interval; P = .01). These trends were observed in patients with LVEF >35% but not in subjects with LVEF ≤35%. Diabetes mellitus, previous coronary artery bypass graft, and amiodarone therapy have diminished the intergroup differences significantly. CONCLUSIONS Heart rate turbulence is diminished in postinfarction patients with a history of malignant ventricular arrhythmias. It seems to separate subjects at arrhythmic risk among patients with relatively preserved left ventricle function, but it is diminished in patients with previous coronary artery bypass graft, diabetes, and amiodarone therapy.

Risk factors and prognostic role of an electrical storm in patients after myocardial infarction with an implanted ICD for secondary prevention

Introduction The aim of our study was to determine the risk factors for electrical storm (ES) and to assess the impact of ES on the long-term prognosis in patients after myocardial infarction (MI) with an implantable cardioverter-defibrillator (ICD) for secondary prevention of sudden cardiac death (SCD). Material and methods We retrospectively analyzed 416 patients with coronary artery disease after MI who had an implanted ICD for secondary prevention of SCD. Fifty (12%) patients had one or more incidents of an electrical storm – the ES (+) group. We matched the reference group of 47 patients from 366 ES (–) patients. Results We analyzed 3,408 episodes of ventricular arrhythmias: 3,148 ventricular tachyarrhythmic episodes in the ES (+) group (including 187 episodes of ES) and 260 in the ES (–) group. Multivariate logistic regression showed that inferior wall MI (RR = 3.98, 95% CI: 1.52–10.41) and the absence of coronary revascularization (RR = 2.92, 95% CI: 1.18–7.21) were independent predictors of ES (p = 0.0014). During 6-year observation of 97 patients, there were 39 (40%) deaths: 25 (50%) subjects in the ES (+) group and 14 (30%) in the ES (–) group (p = 0.036). Independent predictors of death were: the occurrence of ES (HR = 1.93), older age (HR = 1.06), and lower left ventricular ejection fraction (HR = 0.95) (for all p < 0.001). Conclusions Electrical storm in patients after MI with ICD for secondary prevention is a relatively common phenomenon and has a negative prognostic significance. Myocardial infarction of the inferior wall and the absence of coronary revascularization are predisposing factors for the occurrence of an ES.

Dynamicity of Early and Late Phases of Repolarization in Patients with Remote Anterior Myocardial Infarction: The Interlead Differences

Background: Repolarization dynamicity (QT/RR) is supposed to be a prognostic marker in post‐MI patients. However, data on the relationships between early and late phases of QT and RR intervals (QT peak/RR and T peak–T end/RR) are insufficient, and which ECG lead should be used for the analysis is unclear. We analyzed repolarization dynamicity in patients after anterior MI with and without VT/VF history using two leads of Holter recordings‐ modified V5 and V3. The daytime and nighttime periods were also analyzed.