scholarly journals Increased guanylate cyclase activity is associated with an increase in cyclic guanosine 3',5'-monophosphate in left ventricular hypertrophy.

1996 ◽  
Vol 98 (3) ◽  
pp. 838-845 ◽  
Author(s):  
J D Sadoff ◽  
P M Scholz ◽  
J Tse ◽  
H R Weiss
1995 ◽  
Vol 268 (2) ◽  
pp. H686-H691 ◽  
Author(s):  
H. R. Weiss ◽  
E. Rodriguez ◽  
J. Tse

We tested the hypothesis that increases in guanosine 3',5'-cyclic monophosphate (cGMP) would reduce myocardial O2 consumption and that thyroxine (T4)-induced (0.5 mg/kg for 16 days) cardiac hypertrophy would change this relationship. Anesthetized open-chest New Zealand White rabbits were divided into four groups: control vehicle (CV, n = 7), control nitroprusside (CN, n = 6), T4 vehicle (T4V, n = 8), and T4 nitroprusside (T4N, n = 8). Vehicle or sodium nitroprusside (10(-4) M) was topically applied to the left ventricular subepicardium for 15 min. Coronary blood flow (radioactive microspheres) and O2 extraction (microspectrophotometry) were used to determine O2 consumption. Guanylate cyclase activity and cGMP were determined by radioimmunoassay. T4 increased the heart weight-to-body weight ratio from 2.7 +/- 0.1 to 3.4 +/- 0.2. Topical application of nitroprusside had no significant hemodynamic effects. Nitroprusside significantly increased myocardial cGMP in control hearts (CV = 4.1 +/- 0.3 to CN = 12.4 +/- 5.0 pmol/g) and T4 hearts (T4V = 3.9 +/- 0.3 to T4N = 5.2 +/- 0.4). The increase in the level of myocardial cGMP was significantly greater in CN (+202%) than in T4N (+33%). There were no significant differences in basal or total guanylate cyclase activity between control and T4 rabbits. Myocardial O2 consumption significantly declined in both groups during nitroprusside (10.8 +/- 1.4 for CV to 7.3 +/- 1.0 for CN (-32%) and 13.6 +/- 1.2 for T4V to 9.9 +/- 1.4 ml O2.min-1.100 g-1 for T4N (-27%).(ABSTRACT TRUNCATED AT 250 WORDS)


2014 ◽  
Vol 19 (2) ◽  
pp. 11-15
Author(s):  
Steven L. Demeter

Abstract The fourth, fifth, and sixth editions of the AMA Guides to the Evaluation of Permanent Impairment (AMA Guides) use left ventricular hypertrophy (LVH) as a variable to determine impairment caused by hypertensive disease. The issue of LVH, as assessed echocardiographically, is a prime example of medical science being at odds with legal jurisprudence. Some legislatures have allowed any cause of LVH in a hypertensive individual to be an allowed manifestation of hypertensive changes. This situation has arisen because a physician can never say that no component of LVH was not caused by the hypertension, even in an individual with a cardiomyopathy or valvular disorder. This article recommends that evaluators consider three points: if the cause of the LVH is hypertension, is the examinee at maximum medical improvement; is the LVH caused by hypertension or another factor; and, if apportionment is allowed, then a careful analysis of the risk factors for other disorders associated with LVH is necessary. The left ventricular mass index should be present in the echocardiogram report and can guide the interpretation of the alleged LVH; if not present, it should be requested because it facilitates a more accurate analysis. Further, if the cause of the LVH is more likely independent of the hypertension, then careful reasoning and an explanation should be included in the impairment report. If hypertension is only a partial cause, a reasoned analysis and clear explanation of the apportionment are required.


VASA ◽  
2013 ◽  
Vol 42 (4) ◽  
pp. 284-291 ◽  
Author(s):  
Seong-Woo Choi ◽  
Hye-Yeon Kim ◽  
Hye-Ran Ahn ◽  
Young-Hoon Lee ◽  
Sun-Seog Kweon ◽  
...  

Background: To investigate the association between ankle-brachial index (ABI), left ventricular hypertrophy (LVH) and left ventricular mass index (LVMI) in a general population. Patients and methods: The study population consisted of 8,246 people aged 50 years and older who participated in the baseline survey of the Dong-gu Study conducted in Korea between 2007 and 2010. Trained research technicians measured LV mass using mode M ultrasound echocardiography and ABI using an oscillometric method. Results: After adjustment for risk factors and common carotid artery intima-media thickness (CCA-IMT) and the number of plaques, higher ABIs (1.10 1.19, 1.20 - 1.29, and ≥ 1.30) were significantly and linearly associated with high LVMI (1.10 - 1.19 ABI: β, 3.33; 95 % CI, 1.72 - 4.93; 1.20 - 1.29 ABI: β, 6.51; 95 % CI, 4.02 - 9.00; ≥ 1.30 ABI: β, 14.83; 95 % CI, 6.18 - 23.48). An ABI of 1.10 - 1.19 and 1.20 - 1.29 ABI was significantly associated with LVH (1.10 - 1.19 ABI: OR, 1.35; 95 % CI, 1.19 - 1.53; 1.20 - 1.29 ABI: OR, 1.59; 95 % CI, 1.31 - 1.92) and ABI ≥ 1.30 was marginally associated with LVH (OR, 1.73; 95 % CI, 0.93 - 3.22, p = 0.078). Conclusions: After adjustment for other cardiovascular variables and CCA-IMT and the number of plaques, higher ABIs are associated with LVH and LVMI in Koreans aged 50 years and older.


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