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Biomedical subjects

J V Talano

Publications and source records attributed to J V Talano.

At least 19 recordsLinked to original sources
PubMed1992

A Doppler guided retrograde catheterization system.

A Doppler guided retrograde catheterization system was developed to accurately catheterize the aortic root and left ventricular chamber without X-ray. This system consists of a 20 MHz, 0.076 mm thick x 1.016 mm diameter pulsed Doppler crystal integrated into the tip of a 100 cm multipurpose triple lumen catheter. Two lumens (0.61 mm) are used for electrodes; a third lumen (1.245 mm) may be used for guidewire and pressure determination; and the system is attached to a flow velocimeter. In an aortic arch flow model, the principles of Doppler signal guidance were confirmed with flow toward the catheter tip demonstrating positive signals and flow away from the catheter tip demonstrating negative signals. The magnitude and polarity (direction) of the detected phasic and mean velocities were utilized to guide catheterization in six dogs. Using the reversal of Doppler signal polarity to indicate branch entry and manipulating the catheter so as to maintain maximal positive axial velocity, the Doppler catheter was successfully advanced from the femoral artery to the aortic valve. Branches detected by the Doppler system were confirmed by fluoroscopy. The aortic valve was audible when approached and the left ventricular chamber was recognized by its characteristic pressure waveform. The Doppler guided retrograde catheterization system offers new technology to perform left heart catheterization without X-ray and may prove useful in a variety of settings including the development of invasive ultrasonic diagnostic and therapeutic technology.

Animals↗
PubMed1979

Acquired cyanotic heart disease secondary to traumatic tricuspid regurgitation. Case report with a review of the literature.

A case of traumatic tricuspid insufficiency leading to right atrial enlargement and to a patent foramen ovale with right to left shunting is presented. Six similar cases previously reported are reviewed. The time course of clinical deterioration was related to the type of tricuspid valve damage incurred. Papillary muscle rupture led to surgery within a year, whereas less severe chordal damage allowed a more benign course that lasted from 10 to 25 years from the time of injury to the time of surgery. Surgical repair of the incompetent tricuspid valve and closure of the atrial septal defect led to significant improvement. The diagnostic usefulness of radionuclide imaging and echocardiography is demonstrated in this case. A mechanism of right to left interatrial shunting in the presence of normal pulmonary arterial pressures is proposed; this invokes phasic increases in right atrial pressure from tricuspid insufficiency and streaming of blood from the inferior vena cava into the left atrium across a patent foramen ovale in a manner that resembles conditions in the fetal circulation.

Adult↗
PubMed1979

The unbalanced heart. Animal models of cardiac dysrhythmias.

The heart often appears to function independently because it can maintain regular activity even when isolated from the rest of the body. Likewise, it maintains its regularity in the midst of powerful but balanced neural and pressure influences. Experimental situations designed to unbalance these forces produce rhythm disturbances resembling those encountered clinically. Unbalancing of the sympathetic supply with the parasympathetic supply totally obliterated, leads to tachycardias of various origin which are eliminated by adrenergic blockade. Removing the sinoatrial node results in atrial brady-tachyarrhythmia, eliminated by cholinergic blockade. Unbalancing the pressure load results in premature ventricular contractions that are clearly not mediated by external neural controls. Cardiac rhythm disturbances thus result from a variety of forces that may be readily tolerated when balanced by opposing forces but cannot be controlled without that buffer.

Animals↗
PubMed1978

Sinus node dysfunction. An overview with emphasis on autonomic and pharmacologic consideration.

Sinus node dysfunction is a disorder of impulse generation and impulse conduction. Previous works have emphasized that the dysfunction occurs not only within the sinus node but also within the escape pacemaker. Adrenergic and cholinergic mechanisms, as well as pulsations and pressure within the sinus node artery, play an important role in normal sinus node activity. Although perinodal fibers act as a buffer zone for sinoatrial conduction, their role in man is yet to be clarified. During normal sinus node activity, pacemaker shifts from the sinus node to the crista terminalis have been shown to occur. Following sinus node destruction, similar shifts do occur. Clinical methods of determining sinus node function, such as the sinus node recovery time and sinus atrial conduction time, are useful but have limitations. Dynamic electrocardiographic monitoring provides the best clinical method available for detecting sinus node dysfunction. Digitalis appears to improve the parameters of sinus node function by increasing the automaticity of latent atrial pacemakers. The atrial arrhythmia of sinus node dysfunction appears to be related to the characteristics of latent atrial pacemaker and "enhanced" cholinergic tone.

Arrhythmias, Cardiac↗
PubMed1978

Effects of pharmacologically-induced hypertension on myocardial ischemia and coronary hemodynamics in patients with fixed coronary obstruction.

Twenty patients with fixed coronary artery obstruction were studied during rapid atrial pacing and methoxamine infusion. During pacing to heart rates of 142 +/- 4 (mean +/- SEM) beats per minute coronary sinus flow increased from 108 +/- 8 to 187 +/- 15 cc/min and myocardial oxygen consumption increased by + 80 +/- 11%. During methoxamine infusion that raised arterial systolic pressure to 196 +/- 5 mm Hg, similar increases in coronary sinus flow (to 179 +/- 13 cc/min) and myocardial oxygen consumption (+ 77 +/- 12%) occurred. Chest pain and ischemic ST segment changes developed in 17 and 14 patients respectively during atrial pacing, an incidence significantly greater (P less than 0.05) than during infusion of methoxamine (6 and 3 patients). Myocardial lactate extraction which averaged 26 +/- 4% during control was decreased to 10 +/- 8% during pacing and to 24 +/- 7% during methoxamine; the difference between decreases was not significant. The data show that at similar increases in myocardial oxygen consumption stress of increased heart rate results in more myocardial ischemia than stress of increased afterload.

Blood Flow Velocity↗
PubMed1978

Echocardiographic interpretation of pericardial effusion.

Echocardiography has proved to be quite useful in the detection of pericardial effusion. As little as 15 ml of fluid within the pericardial space can be detected. Specific signs of pericardial effusion, such as electrical alternans and paradoxical pulse, have become better understood by echocardiographic study. Yet, with all the benefits of echocardiography, the detection of pericardial effusion still may be quite difficult if careful attention is not given to technique. False-positive diagnosis of anterior pericardial effusion can be seen with epicardial fat pad, pericardial cyst, or foramen of Morgagni hernia. False-positive posterior pericardial effusion can be seen in large left pleural effusion, calcified mitral anulus, or excessively medial transducer angulation. New "switched-gain" circuits have helped detection of pericardial effusion by enhancement of pericardial echoes.

Echocardiography↗
PubMed1977

Granulomatous myocarditis secondary to cornstarch.

A 44-year-old white female with chronic rheumatic heart disease and mitral insufficiency was admitted to the hospital for cardiac catheterization and mitral valve replacement. On the ninth postoperative day the patient experienced a sudden onset of chest pain, hypotension, and died shortly therafter. Autopsy revealed multiple mural thrombi of the left atrium, one of which occluded the mitral orifice. Histologic examination showed a granulomatous and non-specific interstitial myocarditis involving all chambers of the heart. In the granulomas, both inside and outside giant cells, rounded foreign bodies were noted which stained light blue with hematoxylin and eosin, red with the periodic acid Schiff reagent, dark bluish-black with Gram's iodine, and showed Maltese cross birefringence under polarized light. These particles were identical with starch granules from surgical glove powder. The cause of death was acute mitral occlusion form a flapping mural thrombus.

Adult↗
PubMed1977

Refractory ventricular arrhythmia: the role of intraoperative electrophysiological study.

Thirty patients with drug refractory ventricular tachycardia (RVT) were studied between 1 week and 5 years after myocardial infarction with coronary agniography and left ventriculography. They were divided into four groups: (1) inoperable, five patients; (2, a) operated, with primary left ventricular failure, five patients; (2, b) operated with primary RVT, not mapped, 15 patients; (2, c) operated, with mapping, five patients. The mortality rate in group 1 was 100%, and in group 2, a it was 80%. In group 2, b, despite aggressive drug therapy and operation, including aneurysmectomy, coronary revascularization, and intra-aortic balloon pumping when appropriate, the mortality rate wad intraoperative mapping in group 2, c. Arrhythmogenic foci were identified and removed in four. There was one operative death (20%) and four patients are alive from 12 to 27 months after operation, three of whom are asymptomatic. Intraoperative epicardial mapping is an important adjunct to surgery for RVT.

Aged↗
PubMed1976

Esophageal echocardiography.

Esophageal echocardiography has been developed for use in patients with chronic obstructive pulmonary disease and is a safe diagnostic procedure which provides high resolution mirror image echoes of many cardiac structures. Conventional anterior and esophageal echocardiograms were performed in 38 subjects. Esophageal echoes were of diagnostic quality in all 38 subjects, anterior echoes were of diagnostic quality in only 18. Measurements from anterior and esophageal echocardiograms correlated well for aortic valve diameter (r = 0.87), left atrium diameter (r = 0.96), mitral valve EF slope (r = 0.97) and less well for aortic root diameter (r = 0.69).

Echocardiography↗