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Biomedical subjects

I Panidis

Publications and source records attributed to I Panidis.

9 recordsLinked to original sources
PubMed1986

Effects of esmolol on patients with left ventricular dysfunction.

This study examined the effect of esmolol, an ultrashort-acting beta-receptor blocker, in 10 patients with severe left ventricular dysfunction. Simultaneous hemodynamic and radionuclide angiographic measurements were obtained at incremental doses of esmolol (2, 4, 8, 12 and 16 mg/min). At a dose of 4 mg/min, esmolol produced beats blockade: a decrease in heart rate from 91 +/- 4 to 83 +/- 4 beats/min (p less than 0.05) (mean +/- SEM) and a decrease in systolic aortic pressure from 133 +/- 5 to 128 +/- 5 mm Hg (p less than 0.05). At the maximal dose, the heart rate decreased to 79 +/- 3 beats/min (p less than 0.05) and biventricular function was depressed; the left ventricular ejection fraction decreased from 27 +/- 2 to 21 +/- 2% (p less than 0.05) and the right ventricular ejection fraction decreased from 38 +/- 2 to 29 +/- 2% (p less than 0.05). These changes were accompanied by increases in left ventricular end-diastolic volume (p less than 0.05), left ventricular end-systolic volume (p less than 0.05) and pulmonary artery wedge pressure (p less than 0.05), as well as a decrease in cardiac output (p less than 0.05). The hemodynamic abnormalities (which showed considerable interindividual variability) returned to near baseline levels 10 to 30 minutes after infusion was stopped. Thus, esmolol can be administered to patients with severe left ventricular dysfunction. The beneficial effect (beta-adrenergic blockade) is usually achieved with small doses without clinically important hemodynamic changes. At larger doses, however, significant changes in biventricular function may be observed.

Adrenergic beta-Antagonists↗
PubMed1984

The cardiokymography exercise test compared to the thallium-201 perfusion exercise test in the diagnosis of coronary artery disease.

To determine the usefulness of exercise cardiokymography (CKG) compared to thallium-201 perfusion scanning in the diagnosis of coronary artery disease (CAD), 179 patients with a mean age of 54 +/- 10 years (73% men) were studied. Previously documented CAD was present in 73 patients (41%); 13 (7%) were asymptomatic and 93 (53%) had chest pain syndrome. Exercise stress testing, CKG, and thallium-201 perfusion scanning were independently correlated with coronary angiographic data. Treadmill exercise stress test alone without CKG had a sensitivity of 68% and specificity of 62%. CKG showed a sensitivity of 76% and a specificity of 90%, and easily interpreted cardiokymograms were obtained in 78% of patients studied. Thallium-201 scans had a sensitivity of 79% and a specificity of 88%. However, when the CKG and treadmill exercise test results were concordant (both positive or both negative), the CKG exercise test had a sensitivity of 87% and specificity of 100%. Thus, when the CKG and exercise test results are concordant, the sensitivity and specificity are equal to or better than thallium-201 perfusion scanning for the prediction of CAD. Since CKG is an inexpensive and noninvasive test, its adjunctive use with routine exercise stress testing may be of great value.

Adolescent↗
PubMed1984

Calcification of the tricuspid anulus diagnosed by two-dimensional echocardiography.

An 84-year-old female who previously underwent repair of an atrial septal defect had evidence of increased reflectiveness of the posterior tricuspid anulus in the apical four-chamber view and the right ventricular two-chamber view. In addition, the inferior vena cava was dilated and during contrast echocardiography, contrast echoes appeared during systole suggesting tricuspid regurgitation. Tricuspid annular calcification was confirmed by fluoroscopic examination. Tricuspid annular calcification is extremely rare and in the present series occurred in 1 of 80 patients with mitral annular calcification. Lateral resolution echoes from a calcified aortic valve and echoes originating from a calcified right coronary artery have to be distinguished from tricuspid annular calcification.

Aged↗
PubMed1983

Noninvasive evaluation of normal and abnormal prosthetic valve function.

Noninvasive techniques are helpful in evaluating the function of mechanical prostheses and tissue valves. Combined phonocardiography and M-mode echocardiography together with cinefluoroscopy are the most useful noninvasive techniques in differentiating normal from abnormal metallic prosthetic valve function. The intensity of the opening and closing clicks and associated murmurs will depend on the type of prosthetic valve, the heart rate and rhythm and the underlying hemodynamic status. Arrhythmias or conduction disturbances, or both, may produce motion patterns that mimic some of the echocardiographic signs of malfunctioning prosthetic valves. Differentiation of thrombus formation or tissue ingrowth from paravalvular regurgitation or dehiscence is possible by noninvasive techniques. Disc variance, a potentially serious and lethal problem with the older Beall valves, can be readily detected by cinefluoroscopy and echophonocardiography. With regard to bioprosthetic valves, two-dimensional echocardiography is superior to M-mode echocardiography in detecting primary valve failure. In addition, detection of vegetations, valve alignment and ring and individual leaflet motion can be best accomplished by two-dimensional echocardiography. Of greater importance is the patient serving as his or her own control in the follow-up assessment of prosthetic valve function by noninvasive techniques.

Aortic Valve↗
PubMedDate not supplied

Short- and long-term therapeutic efficacy of quinidine sulfate for the treatment of chronic ventricular arrhythmias.

To determine the efficacy and tolerance of oral quinidine sulfate in the treatment of chronic ventricular arrhythmias using contemporary definitions of drug efficacy, 20 ambulatory patients underwent a short-term, placebo-controlled, double-blind trial consisting of four days of quinidine therapy at 400 mg every 6 hours. A long-term trial was conducted in 12 additional patients where ventricular ectopic frequency during two weeks of placebo therapy was compared with that during eight weeks on quinidine sulfate at 300 mg every 6 hours. Quinidine efficacy was determined by 48 hours of Holter monitoring. Blood levels were within the therapeutic range in both trials. Side effects consisted of diarrhea, which occurred in 15 per cent of patients on the short-term and 25 per cent of patients on the long-term trial. Drug effect defined as a statistically significant (P less than 0.025) reduction in chronic premature ventricular complexes occurred in 70 per cent of patients on the short-term trial and in 67 per cent of patients on the long-term trial. In both trials, all patients with ventricular tachycardia had statistically significant suppression. Statistically significant reduction in ventricular couplets occurred in all patients on the short-term trial but in only 73 per cent of the patients on the long-term trial. These data can be used as reference standards for quinidine sulfate in new antiarrhythmic drug comparison trials.

Aged↗
PubMedDate not supplied

In vitro continuous wave Doppler gradients of mechanical valves in less than optimal orientations.

Continuous wave Doppler ultrasound is a noninvasive method of determining transvalvular gradients that may overestimate the gradients of prosthetic valves. It is theorized that a valve rotated or tilted in its annulus will create abnormally high velocities that calculate into derived gradients that are greater than those actually present. An in vitro apparatus was constructed to analyze the velocities and the actual and derived gradients of prosthetic valves in less than optimal orientations. Continuous flow studies of a 27 mm Omniscience prosthesis indicated good agreement between the actual and derived gradients with the valve's major orifice oriented toward the aorta's larger radius. These values increase as the valve is tilted to decrease its net opening angle. When the valve is rotated 180 degrees, the Doppler gradients tend to overestimate the actual pressure drops. These data indicate that certain valve misorientations create velocities that overestimate the transvalvular gradients.

Blood Flow Velocity↗