Right ventricular outflow tract function in chronic heart failure.

BACKGROUND: Heart failure (HF) is a common, progressive, complex clinical syndrome and a subset of HF patients has symptoms out of proportion to the resting hemodynamics and left ventricular ejection fraction (LVEF). Right ventricular (RV) function is a powerful prognostic factor in HF, but assessing it is a challenge because of the right ventricle's complex geometry. OBJECTIVE: The aim of this study was to investigate the clinical application value of RV outflow tract (RVOT) function measured by transthoracic echocardiography in HF patients. METHOD: We prospectively investigated 36 chronic HF patients with dilated heart and LV systolic dysfunction and 21 healthy control subjects (normal ventricular function and ECG, and no cardiac risk factors). In addition to clinical and conventional echocardiographic parameters, RVOT size and fractional shortening (RVOT-FS) parameters were analyzed. RESULTS: The RVOT-FS was less in HF patients than healthy controls (18.8±15.7 vs 55.8±6.7, p<0.001) and correlated positively with TAPSE (r=0.814, p<0.001) and inversely with SPAP (r=-0.728, p<0.001) and functional capacity (r=-0.842, p<0.001). There was a statistically significant difference in RVOT-FS among the HF subgroups with regard to NYHA functional capacity (p<0.001), although there was no statistically significant difference with regard to LVEF. CONCLUSION: Although the apparent discordance between LVEF and the degree of functional impairment in HF is not well understood, it may be explained in part by alterations in RV function. We found that the RVOT-FS was a noninvasive and easily applicable measure of RV function and might be used for a comprehensive evaluation and follow-up of HF patients with a combined assessment of RV by other RV parameters.

Fragmented QRS predicts the arrhythmic events in patients with heart failure undergoing ICD implantation for primary prophylaxis: more fragments more appropriate ICD shocks.

BACKGROUND: Fragmented QRS complex (fQRS) is associated with cardiovascular outcomes in various patient populations. Although there were clinical studies investigating the association of fQRS with arrhythmic events in patients with systolic heart failure, the results were conflicting regarding the association of implantable cardioverter defibrillator (ICD) shocks and fQRS. In this study, we aimed to evaluate the association between the presence and extent of fQRS with appropriate ICD shocks and/or all-cause mortality. METHODS: A total of 215 patients (age: 58.2 ± 11.6 years, 72.5 % male) with the diagnosis of left ventricular systolic heart failure in whom ICD had been implanted for primary prophylaxis were enrolled. Standard ECG evaluation revealed fQRS complex in 123 patients (57.2 %). The phenomenon of fQRS was defined as deflections at the beginning of the QRS complex, on top of the R wave, or in the nadir of the S wave similar to the definition in CAD. RESULTS: At mean 23.5 ± 12.1 months follow-up, all-cause mortality was observed in 45 (20.9 %) patients and 111 (51.6 %) patients experienced appropriate ICD shocks. Median number of ECG leads with fQRS were higher in patients with appropriate ICD shocks (3 [2-6] vs 1 [0-2], P < 0.001, respectively). The presence of fQRS (HR: 6.64, 95 % CI: 3.54-12.4, P < 0.001) and the number of leads with fQRS (HR: 1.35, 95% CI: 1.22-1.67) were found as independent predictors of appropriate ICD shocks. Additionally, there was a negative correlation between left ventricular ejection fraction and the number of leads with fQRS (r = -0.434, P < 0.001). Rates of all-cause mortality did not differ between the fQRS(+) (29 [24 % ]) and fQRS(-) (16 [17 % ]) groups (P = 0.27). CONCLUSION: Our findings suggest that the presence and extent of fQRS complex on standard 12-lead ECG predicts appropriate ICD shocks in patients with left ventricular systolic heart failure who underwent ICD implantation for primary prophylaxis.

Myocardial tissue perfusion predicts the evolution of fragmented QRS in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention.

BACKGROUND: Fragmented QRS complex (fQRS) is associated with worse outcomes in several cardiovascular conditions. However, alterations in fQRS in patients with ST elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) and association of fQRS with myocardial blush grade (MBG) has not been investigated until now. In this study, we aimed to investigate the association of MBG after primary PCI with evolution of fQRS. METHODS: Our study consisted of 401 consecutive patients with STEMI who underwent primary PCI. Patients were categorized into two subgroups according to persistence or new-onset of fQRS (Group 1) and absence or resolution of fQRS (Group 2) at 48 hours after primary PCI. The evolution of fQRS on pre- and post-PCI ECG and their relation with myocardial reperfusion parameters were investigated. RESULTS: Patients in group 1 showed older age, higher rate of smoking, lower HDL-cholesterol, lower LVEF, higher angina-to-door time, higher TIMI frame count, and high rate of patients with MBG <3 compared to patients with group 2 (P < 0.05). In correlation analysis, LVEF showed positive correlation with MBG (r = 0.448, P < 0.001) and negative correlation with the number of leads with fQRS (r = -0.335, P < 0.001). In multivariate regression analysis, new-onset or persistance of fQRS after primary PCI is significantly associated with MBG <3, peak CK-MB level, pre-PCI fQRS at anterior localization and smoking. CONCLUSION: Our findings showed that despite complete ST-segment resolution in all patients, fQRS is independently associated with impaired microvascular myocardial perfusion. So, fQRS, as a simple and easily available noninvasive marker, may be useful in stratification of high-risk patients with increased extent of infarcted myocardium who underwent primary PCI.

Heart rate variability and red cell distribution width in patients with systolic left heart failure.

OBJECTIVE: Red cell distribution width (RDW) is a strong prognostic marker for systolic left heart failure regardless of the anemia status, and heart rate variability (HRV) is negatively associated with mortality and sudden cardiac death in patients with systolic left heart failure. Their relationship has not been investigated in the previous literature. DESIGN: One hundred eighty four patients who had been previously diagnosed with systolic left heart failure (with ischemic or non-ischemic etiology) were retrospectively enrolled in our study. Patients underwent 24-h electrocardiographic monitoring, and blood samples for RDW and other variables were analyzed. Study population was grouped into tertiles of RDW (Tertile 1: 13.4 ± 1.4%, Tertile 2: 14.6 ± 1.4%, and Tertile 3: 17.1 ± 1.2%). RESULTS: Most of the characteristics of patients were similar among RDW tertiles. Standard deviation of all normal RR intervals (SDNN), standard deviation of the averages of RR intervals in all 5-min segments (SDANN) and root-mean square of difference of successive RR intervals (RMSSD) values significantly differed among groups (p < 0.001). The highest RDW tertile had the lowest HRV values, and Pearson correlation analysis yielded a negative correlation between HRV parameters and RDW (for SDNN, SDANN, RMSSD; r = 0.373, 0.340, 0.362, respectively, p < 0.001 for all). In stepwise multivariate analysis HRV was independently associated with RDW. CONCLUSIONS: The HRV parameters were independently associated with RDW in patients with systolic left heart failure.