ABSTRACT
The aim of this paper was to investigate cardiac remodelling in thyrotoxicosis. The geometric parameters of the left ventricle (LV) and the readings of tissue Doppler echocardiography were compared in 27 patients (mean age 53.3±9.2 years) who had first-diagnosed moderate thyrotoxicosis without concomitant cardiac pathology and in 16 healthy individuals (mean age 45.1±4.7 years). The baseline data and the results of incremental treadmill exercise tests were analyzed. It was shown that in the relatively early periods of thyrotoxicosis development, there were decreases in the left ventricle (LV) longitudinally and transversely and in the thickness of LV, without altering its sphericity and conicity. Along with weight loss, there were reductions in cardiac sizes with decreases in the local rates of cardiac wall movement, peak systolic and early diastolic rates of mitral movement velocities. During a treadmill test, there was a drastic reduction in the exercise tolerance threshold as compared to healthy individuals: 57.81±14.7 and 148.3±11.7 W, respectively.
ABSTRACT
The aim of the investigation was to assess the time course of structural-and-functional and spatiogeometric changes following drug correction of euthyroidism in patients with diffuse toxic goiter and to determine prospects for restoring the cardiac functional reserve after elimination of thyrotoxicosis. The geometric parameters of the left ventricle (LV) and the readings of tissue Doppler echocardiography and exercise tests were compared in 27 female patients (mean age 53.3±9.2 years) who had thyrotoxicosis and 6 months after thyrosole-induced normalization of thyroid-stimulating and thyroid hormone. There were significant increases in myocardial mass and peak systolic and diastolic mitral ring motion rates and an increasing trend for LV linear sizes after correction of euthyroidism. Despite the fact that there were no significant differences in the majority of LV geometric parameters, with euthyroidism achievement, the cardiac functional reserve doubled as compared with the baseline values (105.7±11.4 and 57.8±14.7 W, respectively; p < 0.001), but remained below the control level (148.7±11.7 W; p < 0.05), which may contribute to the development of heart failure in future under certain conditions.
ABSTRACT
BACKGROUND: Muscular counterpulsation (MCP) was developed for circulatory assistance by stimulation of peripheral skeletal muscles. We report on a clinical MCP study in patients with and without chronic heart failure (CHF). METHODS AND RESULTS: MCP treatment was applied (30 patients treated, 25 controls, all under optimal therapy) for 30 minutes during eight days by an ECG-triggered, battery-powered, portable pulse generator with skin electrodes inducing light contractions of calf and thigh muscles, sequentially stimulated at early diastole. Hemodynamic parameters (ECG, blood pressure and echocardiography) were measured one day before and one day after the treatment period in two groups: Group 1 (9 MCP, 11 no MCP) with ejection fraction (EF) above 40% and Group 2 (21 MCP, 14 no MCP) below 40%. In Group 2 (all patients suffering from CHF) mean EF increased by 21% (p<0.001) and stroke volume by 13% (p<0.001), while end systolic volume decreased by 23% (p<0.001). In Group 1, the increase in EF (6%) and stroke volume (8%) was also significant (p<0.05) but less pronounced than in Group 2. Physical exercise duration and walking distance increased in Group 2 by 56% and 72%, respectively. CONCLUSIONS: Noninvasive MCP treatment for eight days substantially improves cardiac function and physical performance in patients with CHF.
Subject(s)
Counterpulsation/methods , Heart Failure/therapy , Muscle, Skeletal/physiology , Adult , Electrocardiography , Exercise Test , Female , Heart Failure/physiopathology , Hemodynamics , Humans , Male , Middle Aged , Treatment OutcomeABSTRACT
BACKGROUND: Patients undergoing major vascular surgery are at a relatively high risk of cardiac events, and pharmacological stress echocardiography is increasingly used for perioperative risk stratification. The aim of the current study was to evaluate the value of dipyridamole echocardiography test (up to 0.84 mg/kg over 10 minutes) in predicting cardiac events in a large-scale, multicenter, prospective, observational study design. METHODS AND RESULTS: Five hundred nine patients (mean age 66+/-10 years) were studied before vascular surgery by dipyridamole stress echocardiography in 11 different centers. All patients underwent preoperative clinical risk assessment according to the American Heart Association guidelines. No major complications occurred during dipyridamole stress echocardiography. Technically adequate images were obtained in all patients; however, in 4 patients only the low dipyridamole dose (0.56 mg/kg over 4 minutes) was given for limiting side effects. Eighty-eight (17.3%) had a positive test. Perioperative events occurred in 31 (6.1%) patients: 6 deaths, 11 myocardial infarctions, and 14 episodes of unstable angina. Sensitivity and specificity of dipyridamole stress echocardiography for predicting spontaneous cardiac events were 81% and 87%, respectively, with a positive predictive value of 28% and negative predictive value of 99%. By multivariate analysis, the difference between wall motion score index at rest and peak stress (Deltawall motion score index), test positivity, and ST-segment depression during dipyridamole infusion were independent predictors of any perioperative cardiac event. CONCLUSIONS: Dipyridamole stress echocardiography is safe and well tolerated in patients undergoing major vascular surgery and provides an effective preoperative screening test for the risk stratification of these patients, mainly because of the extremely high negative predictive value, which is a potent predictor of complication-free procedure.
