Increased expression of cytoskeletal, linkage, and extracellular proteins in failing human myocardium.

Experimental studies have shown that in hypertrophy and heart failure, accumulation of microtubules occurs that impedes sarcomere motion and contributes to decreased ventricular compliance. We tested the hypothesis that these changes are present in the failing human heart and that an entire complex of structural components, including cytoskeletal, linkage, and extracellular proteins, are involved in causing functional deterioration. In explanted human hearts failing because of dilated cardiomyopathy (ejection fraction View Article and Find Full Text PDF

The extracellular matrix in hibernating myocardium--a significant factor causing structural defects and cardiac dysfunction.

Recently, we described chronic intracellular degeneration accompanied by fibrosis as typical structural features of hibernating myocardium and we concluded that cellular degeneration as a sign of the incomplete adaptation to the reduced blood flow is characteristic of hibernation. This study has been extended by analyzing the composition of the extracellular matrix proteins of the diseased myocardium. Areas of hibernating myocardium were identified in 38 patients by angiography, multigated radionuclide ventriculography, thallium scintigraphy with reinjection and low-dose dobutamine echocardiography.

Assessment of myocardial viability: Dobutamine echocardiography and thallium-201 single-photon emission computed tomographic imaging predict the postoperative improvement of left ventricular function after bypass surgery.

The aim of this study was to evaluate the usefulness of dobutamine echocardiography and quantitative thallium-201 single photon emission computed tomography myocardial scintigraphy with reinjection in the detection of viable myocardium in patients with coronary artery disease and reduced left ventricular function, which will improve after aortocoronary bypass surgery. Forty-eight patients (47 men, aged 61 +/- 6 years) with angiographically documented reduced left ventricular function (ejection fraction 35 +/- 14, 63% with chronic transmural myocardial infarction) were examined by dobutamine two-dimensional echocardiography (before and during low dosage), 201Tl, and gated radionuclide ventriculography before and 3 +/- 2 months after aortocoronary bypass surgery. Four of 55 areas classified viable before operation were revascularized inadequately and discarded.

Hibernating myocardium: an incomplete adaptation to ischemia.

Background: We tested the hypothesis that hibernating myocardium represents an incomplete adaptation to a reduced myocardial oxygen supply.

Methods And Results: In 38 patients, areas of hibernating myocardium were identified by angiography, multigated radionuclide ventriculography, thallium scintigraphy with reinjection, and low-dose dobutamine echocardiography. Biopsies removed at cardiac surgery showed structural degeneration characterized by a reduced protein and mRNA expression and disorganization of the contractile and cytoskeletal proteins myosin, actin, desmin, titin, alpha-actinin, and vinculin by electron microscopy, immunohistochemistry, and in situ hybridization.

Effect of the addition of an abdominal hot can cardioverter/defibrillator pulse generator on the defibrillation energy requirements in a single-lead endocardial defibrillation system.

Aims: The effects of a cardioverter/defibrillator system with an electrically active generator can, applied without recourse to thoracotomy, have not been investigated in the abdominal position in humans. The purpose of this acute clinical study was to evaluate the defibrillation efficacy of an abdominally positioned hot can electrode in connection with a single lead endocardial defibrillation system.

Patients And Methods: Thirty consecutive patients undergoing implantation of a cardioverter/defibrillator or pulse generator replacement were enrolled in this study Each patient received an integrated, tripolar single-lead system.