Increased Variability of the Coupling Interval of Premature Ventricular Contractions as a Predictor of Cardiac Mortality in Patients With Left Ventricular Dysfunction

Abstract

Background:The characteristics and prognostic value of the variability of premature ventricular contraction (PVC) coupling intervals (CIs) for cardiac mortality are not yet decisive. Methods and Results:In 133 consecutive patients (58±14 years old, 53 women) who had left ventricular dysfunction (LVD: ejection fraction <50%) and frequent PVCs (≥10/h) who underwent 24-h ambulatory electrocardiography (AECG) recording and 123 I-metaiodobenzylguanidine myocardial single-photon emission computed tomography simultaneously, the heart rate turbulence onset, slope, and T-wave alternans were analyzed from the 24-h AECG. The CI of the PVCs (MEANNV), standard deviation of the CI of the PVCs (SDNV) as an index of the variability of the PVC CI, and their ratio to the preceding N-N intervals (SDNV/SDNN) were calculated from constructed Poincaré plots using the annotated 24-h AECG QRS data. The primary endpoint was cardiac mortality. The mean follow-up period was 63 months. Among 133 patients, 114 survived (group 1) and 19 (14%, group 2) died during the follow-up. The MEANNV and SDNV were higher in group 2 (539±104 vs. 599±114 ms, P=0.021; 64±34 vs. 83±37 ms, P=0.022, respectively). The SDNV, PVC count, and delayed heart/mediastinum ratio remained as significant predictors of cardiac mortality in the binary logistic regression analysis. Conclusions:These results suggest that the SDNV could be another adjunctive parameter for predicting cardiac mortality in LVD. (Circ J 2015; 79: 2360 -2366

Neonatal cardiomyocyte hypertrophy induced by endothelin-1 is blocked by estradiol acting on GPER

“…Considering the central role of Akt phosphorylation in protection of the heart, it is possible to speculate that the apparent redundancy of the ER␣ receptor and GPER represents an important adaptative cardioprotective mechanism. Changes in cardiomyocyte contractile profile are related to the development of cardiac dysfunction (36,51). We observed that ET-1 induced a reduction in the frequency of contractile events, whereas blockage of the GPER increased the amplitude and frequency.…”

Premature Ventricular Contraction Coupling Interval Variability Destabilizes Cardiac Neuronal and Electrophysiological Control

“…Particularly, patients with PVCs showing high coupling interval (CI) variability are at a greater risk for cardiac events such as left ventricular (LV) dysfunction 4 and sudden cardiac death. 5, 6 …”

Preliminary Study of Coupling Intervals of Premature Ventricular Complexes in Dogs With Different Cardiac Diseases

“…Computation of heart rate variability is often performed by Poincaré plots, a graphical representation of the correlation between successive R-R intervals as a function of N-N intervals (RRn), but in the case of PVCs, the N-V interval (CI) is displayed as function of the preceding N-N interval. This was software was custom-made for the study by Lee et al (2015) to allow graphical depiction of the SD of all N-V intervals (SD (ms) for both normal and N-V intervals were expressed as a ratio of SDnv/SDnn.…”

“…In contrast, Lerma et al (2013) demonstrated that the presence of a high prevalence of PVCs in 24-hour ECGs in patients, 6 week after myocardial infarction, with low CI variability, was considered a risk marker of fatal or near-fatal arrhythmias. In 2015, Lee et al (2015) examined the morphologies and CIV of PVCs in two groups of patients categorized according to their cardiac mortality (alive or dead), with either ischemic or dilated cardiomyopathy. The mean and standard deviation of all coupling intervals of VPCs were compared to the time domain variables of the normal sinus beats intervals to determine CIV.…”