Differential Alterations in Left and Right Ventricular G-Proteins in Congestive Heart Failure due to Myocardial Infarction

1998 ◽  
Vol 30 (11) ◽  
pp. 2153-2163 ◽  
Author(s):  
Rajat Sethi ◽  
Vijayan Elimban ◽  
Donald Chapman ◽  
Ian M.C. Dixon ◽  
Naranjan S. Dhalla
1985 ◽  
Vol 5 (6) ◽  
pp. 1326-1334 ◽  
Author(s):  
Marvin A. Konstam ◽  
Steven R. Cohen ◽  
Deeb N. Salem ◽  
Thomas P. Conlon ◽  
Jeffrey M. Isner ◽  
...  

1997 ◽  
Vol 272 (2) ◽  
pp. H884-H893 ◽  
Author(s):  
R. Sethi ◽  
K. S. Dhalla ◽  
R. E. Beamish ◽  
N. S. Dhalla

The status of beta-adrenergic receptors and adenylyl cyclase in crude membranes from both left and right ventricles was examined when the left coronary artery in rats was occluded for 4, 8, and 16 wk. The adenylyl cyclase activity in the presence of isoproterenol was decreased in the uninfarcted (viable) left ventricle and increased in the right ventricle subsequent to myocardial infarction. The density of beta1-adrenergic receptors, unlike beta2-receptors, was reduced in the left ventricle, whereas no change in the characteristics of beta1- and beta2-adrenergic receptors was seen in the right ventricle. The catalytic activity of adenylyl cyclase was depressed in the viable left ventricle but was unchanged in the right ventricle. In comparison to sham controls, the basal, as well as NaF-, forskolin-, and 5'-guanylyl imidodiphosphate [Gpp(NH)p]-stimulated adenylyl cyclase activities were decreased in the left ventricle and increased in the right ventricle of the experimental animals. Opposite alterations in the adenylyl cyclase activities in left and right ventricles from infarcted animals were also seen when two types of purified sarcolemmal preparations were employed. These changes in adenylyl cyclase activities in the left and right ventricles were dependent on the degree of heart failure. Furthermore, adenosine 3',5'-cyclic monophosphate contents were higher in the right ventricle and lower in the left ventricle from infarcted animals injected with saline, isoproterenol, or forskolin in comparison to the controls. The results suggest differential changes in the viable left and right ventricles with respect to adenylyl cyclase activities during the development of congestive heart failure due to myocardial infarction.


1997 ◽  
Vol 133 (3) ◽  
pp. 340-345 ◽  
Author(s):  
Pallab K. Ganguly ◽  
Ken S. Dhalla ◽  
Qiming Shao ◽  
Robert E. Beamish ◽  
Naranjan S. Dhalla

2021 ◽  
Vol 8 ◽  
Author(s):  
Wei Lai ◽  
He Jie ◽  
Dong Jian-Xun ◽  
Kong Ling-Cong ◽  
Zeng Jun-Tong ◽  
...  

Background: The impact of concomitant impairments of left and right ventricular (LV and RV) strain on the long-term prognosis of acute ST-elevation myocardial infarction (STEMI) is not clear.Methods: We analyzed CMR images and followed up 420 first STEMI patients from the EARLY Assessment of MYOcardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry (NCT03768453). These patients received timely primary percutaneous coronary intervention (PCI) within 12 h and CMR examination within 1 week (median, 5 days; range, 2–7 days) after infarction. Global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) of both ventricles were measured based on CMR cine images. Conventional CMR indexes were also assessed. Primary clinical outcome was composite major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, re-hospitalization for heart failure and stroke. In addition, CMR data from 40 people without apparent heart disease were used as control group.Results: Compared to controls, both LV and RV strains were remarkably reduced in STEMI patients. During follow-up (median: 52 months, interquartile range: 29–68 months), 80 patients experienced major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, heart failure, and stroke. LV-GCS > −11.20% was an independent predictor of MACCEs (P < 0.001). RV-GRS was the only RV strain index that could effectively predict the risk of MACCEs (AUC = 0.604, 95% CI [0.533, 0.674], P = 0.004). Patient with RV-GRS ≤ 38.79% experienced more MACCEs than those with preserved RV-GRS (log rank P < 0.001). Moreover, patients with the concomitant decrease of LV-GCS and RV-GRS were more likely to experience MACCEs than patients with decreased LV-GCS alone (log rank P = 0.010). RV-GRS was incremental to LV-GCS for the predictive power of MACCEs (continuous NRI: 0.327; 95% CI: 0.095–0.558; P = 0.006). Finally, tobacco use (P = 0.003), right coronary artery involvement (P = 0.002), and LV-GCS > −11.20% (P = 0.012) was correlated with lower RV-GRS.Conclusions: The concomitant decrease of LV and RV strain is associated with a worse long-term prognosis than impaired LV strain alone. Combination assessment of both LV and RV strain indexes could improve risk stratification of patients with STEMI.Trial Registration:ClinicalTrials.gov, NCT03768453. Registered 7 December 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03768453.


1992 ◽  
Vol 262 (3) ◽  
pp. H868-H874 ◽  
Author(s):  
N. Afzal ◽  
N. S. Dhalla

To examine the status of sarcoplasmic reticulum (SR) with respect to Ca2+ transport in congestive heart failure due to myocardial infarction, the left coronary artery in rats was ligated for 4, 8, and 16 wk. The left heart function was assessed with an intraventricular pressure transducer, and SR membrane fractions from the right ventricle and the viable left ventricle were isolated for measuring the ATP-dependent Ca2+ uptake activities. In comparison to sham-operated controls, SR Ca2+ uptake activity was decreased in viable left ventricle of the experimental animals at 4, 8, and 16 wk. On the other hand, SR Ca2+ uptake activity in the right ventricle was increased at 4 and 8 wk, but no change was apparent at 16 wk of coronary occlusion. The decrease in SR Ca2+ uptake in left ventricle and increase in right ventricle were associated with corresponding changes in maximal velocity values without any alterations in the affinity for Ca2+. These opposite changes in the right and left ventricles were dependent on the scar size as well as time after inducing the myocardial infarction. The SR Ca(2+)-stimulated adenosinetriphosphatase activity was decreased in left ventricle and increased in the right ventricle from 4 wk experimental animals. The results suggest differential remodeling of the SR membranes with respect to Ca(2+)-pump mechanisms in left and right ventricles during the development of congestive heart failure.


2001 ◽  
Vol 65 (9) ◽  
pp. 803-807 ◽  
Author(s):  
Tetsuro Ohta ◽  
Satoshi Nakatani ◽  
Shiro Izumi ◽  
Seiki Nagata ◽  
Shintaro Beppu ◽  
...  

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