PubMed Health⌕ Search

Biomedical subjects

V A Gaudiani

Publications and source records attributed to V A Gaudiani.

29 records · Page 2Linked to original sources
PubMed1978

Limits of myocardial protection with potassium cardioplegia.

Preservation of left ventricular function with various potassium-based cardioplegic solutions has been considered to be effective for at least 60 minutes during occlusion of the ascending aorta. The purpose of this study was to define the limits of protection offered by potassium alone. A single bolus of 150 ml of potassium (24 mEq per liter) in normal saline solution at 30 degrees C was injected in the aortic roots of foxhounds at the initiation of periods of 45 minutes, 60 minutes, and 75 minutes of aortic occlusion at a core temperature of 30 degrees C. Data derived from postischemic recovery phase ventricular function curves and force-velocity relations demonstrated excellent protection during 45 minutes of ischemia, inconsistent protection at 60 minutes, and poor protection at 75 minutes.

Animals↗
PubMed1978

Intraoperative, intracardiac echocardiography during left ventriculomyotomy and myectomy for hypertrophic subaortic stenosis.

In 15 patients undergoing left ventriculomyotomy and myectomy for idiopathic hypertrophic subaortic stenosis (IHSS), the thickness of the interventricular septum was measured before and after muscle resection by means of a modified sternal-notch pediatric ultrasound transducer. Preoperative and intraoperative measurements by echogram were highly correlated (r = 0.92, P = 0.6), and accurately predicted the dimensions of the excised bar of muscle (r = 0.98, P = 0.6). The mean depth of the trough created at operation was 9.7 +/- 0.8 mm, and the mean thickness of the septum remaining was 14.3 +/- 0.9 mm. When studied 6 months postoperatively, all surviving patients were functionally improved, and none had a pressure gradient when studied in the resting state. However, two-thirds of the patients had residual provocable gradients (decreased by 70% from those preoperatively). Intraoperative echogram measurements failed to correlate with the presence or extent of the postoperative provocable gradients. Intraoperative echocardiography provides imaging of dimensions otherwise unavailable, and may help define the characteristics of the myectomy that result in uniform symptomatic and hemodynamic benefit.

Cardiac Surgical Procedures↗
PubMed1978

Continuous epicardial echocardiographic assessment of postoperative left ventricular function.

An ultrasound transducer which is sutured to the heart at operation and removal percutaneously has been developed and tested in 20 animals. The potential of this device to monitor cardiac function was measured by simultaneously recording 67 left ventricular angiograms and echograms over a wide range of hemodynamic function. In addition, the reproducibility of the data obtained from the transducer and the safety of application and withdrawal were examined. We found highly significant (p less than 0.005) linear correlation between echocardiographic and angiographic measurements of left ventricular end-diastolic volume, end-systolic volume, and ejection fraction. This transducer may provide the means to assess left ventricular size and ejection fraction continuously after cardiac operations in man.

Animals↗
PubMed1978

Alterations in regional contractility following cardiopulmonary bypass with intraoperative ischemia.

Coronary occlusion during cardiopulmonary bypass has been used in place of aortic occlusion to perform coronary artery anastomoses, but this procedure on distal myocardial function has not been evaluated. Regional myocardial function was examined with the use of ultrasonic crystals in 20 dogs subjected to this technique to compare normothermic and hypothermic (30 degrees C) bypass in both beating and fibrillating hearts. We found a significant decline in the velocity of contraction of the distal segment in fibrillating compared to bearing hearts (p less than 0.01). Hypothermia prevented this decline in the beating, but not the fibrillating, hearts. With respect to contractile function in the distal myocardial segment, local occlusion techniques cause an injury similar to that reported for aortic cross-clamping.

Animals↗
PubMed1975

Cardiac tamponade.

Cardiac tamponade is an insidious and often fatal complication which can occur on any service, in many diseases, and at any age. The increasing pressure within the pericardium prevents ventricular filling and depresses cardiac output, coronary and systemic perfusion, and venous return. Compensatory mechanisms may protect the patient for some time, but prompt diagnosis and rapid decompression are usually required and must be followed by meticulous evaluation and treatment of the underlying disease.

Cardiac Tamponade↗
PubMedDate not supplied

A biologically compatible implantable ultrasonic marker.

An implantable passive ultrasonic marker has been developed which can be detected with a conventional pulse echo imaging system. The marker consists of a planar array of 1/16 in. diameter stainless steel (316L) spheres and produces a distinct and characteristic reflection signature due to reverbation within the spheres. The marker has undergone both in vitro and in vivo tests and is biologically compatible for chronic implantation. It is consistently detectable at depths up to 10 cm from the transducer. An application to the detection of flow conditions in aortocoronary bypass grafts is suggested.

Animals↗
PubMedDate not supplied

Method for cardiac transplantation in corrected transposition of the great arteries.

A patient with corrected transposition of the great vessels (L-transposition) required cardiac transplantation because of severe myopathy of th systemic ventricle of right ventricular morphology. Because of the L-transposition of the great vessels, a modification of the transplantation procedure was necessary in order to make the great vessel anastomoses. This was accomplished without the need for prosthetic material primarily by extensive removal of donor pulmonary artery and aorta together with the heart. Anastomosis of the recipient ascending aorta was accomplished to the superior aspect of the transverse aortic arch of the donor, and the recipient pulmonary artery to the superior portion of the right pulmonary artery of the donor. The postoperative hemodynamics were normal and a thoracic aortogram one year post-transplant demonstrated the unusual anatomy.

Adult↗