We developed a new technique to evaluate regional myocardial elastance using minute vibration. In 13 isolated cross-circulated canine hearts, we applied small sinusoidal vibrations of displacement to the left ventricular surface at various frequencies (50-100 Hz). Using the measured displacement and force between the vibrator head and myocardium, we derived myocardial elastance on the basis of the equation of motion for a given moment of the cardiac cycle. Simultaneous solution of the equations of motion at different frequencies yielded a unique value of elastance. Time-varying myocardial elastance increased from diastole (0.028 +/- 0.211 x 10(6) dyn/cm) to systole (0.833 +/- 0.391 x 10(6) dyn/cm). The end-systolic elastance (ees) linearly correlated with end-systolic left ventricular elastance (r = 0.717, P < 0.001) and also with the end-systolic Young's modulus (r = 0.874, P < 0.0001). We also measured ees at both ischemic and nonischemic regions during coronary occlusion. Young's modulus, estimated by normalizing ees by the wall thickness and by the estimated mass, did not change significantly at the nonischemic regions, whereas it decreased significantly from 2.303 +/- 0.556 to 1.173 +/- 0.370 x 10(6) dyn/cm2 at the ischemic region after coronary occlusion (P < 0.005). We conclude that this technique is useful for the quantitative assessment of regional myocardial elastance.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1152/ajpheart.1998.274.4.H1404 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Bi-ventricular elastic material parameters estimation using 3D CMR myocardial strains in rheumatic heart disease patients.
J Biomech
January 2025
Division of Cardiology, Department of Medicine, University of Cape Town, Cape Town, South Africa; Cape Universities Body Imaging Centre, Faculty of Health Sciences, University of Cape Town, South Africa; South African Medical Research Council Extramural Unit on Intersection of Noncommunicable Diseases and Infectious Diseases. Electronic address:
Understanding the elastic material behavior of myocardium during the diastolic phase is critical for evaluating cardiac function and improving treatments for diastolic abnormalities. This study introduces a novel multi-objective optimization framework that incorporates both strain and volume measurements to enhance the accuracy of myocardial property assessments in Rheumatic Heart Disease (RHD) patients and healthy controls. By employing global volume and strain measurements instead of segmented strains from the sixteen AHA regions, we achieve a robust alignment with the Klotz curve across all groups, indicating an accurate simulation of end-diastolic pressure-volume relationships (EDPVRs).
View Article and Find Full Text PDFStructural and Functional Remodeling for Elite Cyclists During Exercise; Pressure Volume Loops and Hemodynamic Forces Analysis.
Am J Physiol Heart Circ Physiol
January 2025
Sport Medicine Unit, Careggi University Hospital, Via delle Oblate 4, 50134 Florence, Italy.
The study was designed to investigate the pattern of intraventricular Hemo-Dynamic Forces (HDF) and myocardial performance during exercise in Elite Cyclists (EC). Transthoracic stress echocardiography was performed on nineteen EC and thirteen age-matched sedentary controls (SC) at three incremental exercise intensities based on Heart Rate Reserve (HRR). Left Ventricular (LV) HDF were computed from echocardiography long-axis data sets using a novel technique based on endocardial boundary tracking, both in apex-base and latero-septal directions.
View Article and Find Full Text PDFElevated Plasma Nitrate Levels in Patients with Acute Coronary Syndrome.
Am J Cardiol
January 2025
Department of Cardiology, Apollo Institute of Medical Science and Research, Apollo Health City, Hyderabad, Telangana, India.
Acute coronary syndrome (ACS) encompasses a spectrum of coronary artery diseases, including unstable angina, non-ST segment elevation myocardial infarction, and ST-segment elevation MI. At present, ACS is a major cause of mortality and morbidity in the community. The diagnosis of ACS is of critical importance for guiding appropriate therapeutic strategies, although this can be onerous if the standard presenting manifestations are lacking.
View Article and Find Full Text PDFDulaglutide and Dapagliflozin Combination Concurrently Improves the Endothelial Glycocalyx and Vascular and Myocardial Function in Patients with T2DM and Albuminuria vs. DPP-4i.
J Clin Med
December 2024
2nd Department of Internal Medicine Research Unit and Diabetes Centre, Attikon Hospital, Medical School, National and Kapodistrian University of Athens, Rimini 1 Str., Chaidari, 12462 Athens, Greece.
: The association between diabetic nephropathy and arterial elasticity and endothelial function is well established. In this study, we compared the effect of the combination of dulaglutide and dapagliflozin versus DPP-4 inhibitors on the endothelial glycocalyx, arterial stiffness, myocardial function, and albuminuria. : Overall, 60 patients were randomized to combined dulaglutide and dapagliflozin treatment (n = 30) or DPP-4 inhibitors (DPP-4i, n = 30) (ClinicalTrials.
View Article and Find Full Text PDFDiscovery of Titin and Its Role in Heart Function and Disease.
Circ Res
January 2025
Department of Integrative Pathophysiology, Medical Faculty Mannheim, DZHK Partnersite Mannheim-Heidelberg, University of Heidelberg, Germany (S.L.).
This review examines the giant elastic protein titin and its critical roles in heart function, both in health and disease, as discovered since its identification nearly 50 years ago. Encoded by the TTN (titin gene), titin has emerged as a major disease locus for cardiac disorders. Functionally, titin acts as a third myofilament type, connecting sarcomeric Z-disks and M-bands, and regulating myocardial passive stiffness and stretch sensing.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!