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Biomedical subjects

D Harpaz

Publications and source records attributed to D Harpaz.

30 records · Page 2Linked to original sources
PubMed1993

Ultrasound enhancement of thrombolysis and reperfusion in vitro.

OBJECTIVES: The aims of this study were 1) to develop an in vitro flow system in which reperfusion mediated by ultrasound-accelerated thrombolysis could be studied, and 2) to test whether ultrasound-accelerated thrombolysis could hasten reperfusion in this system. BACKGROUND: Ultrasound has been shown to increase tissue plasminogen activator (t-PA)-induced thrombolysis in vitro as assessed by radioactive fibrinogen release from labeled clots and in an animal in vivo model. METHODS: To test whether reperfusion is accelerated, we created obstructive whole blood clots in an in vitro flow system. Four control clots were exposed to ultrasound only without any thrombolytic agent (group 1). Sixteen clots were exposed to continuous infusion of recombinant tissue-type plasminogen activator rt-PA and randomized to either continuous wave ultrasound exposure at a frequency of 0.5 MHz and an intensity of 8 W/cm2 (group 2) or to no ultrasound (group 3). Flow distal to the clot and the rate of release of radiolabeled fibrin products were used as an index of reperfusion and thrombolysis, respectively. Samples were obtained for measurements of lytic variables such as plasminogen, fibrinogen and rt-PA concentrations. RESULTS: Flow was significantly higher in the rt-PA-treated clots within 10 min of exposure to ultrasound than in those without such exposure (9.4 +/- 9.9% of maximal flow in group 2 vs. 0.5 +/- 1.5% in group 3, p < 0.05). The maximal difference in flow between groups 2 and 3 was achieved at 25 min (61.0 +/- 30.4% vs. 14.2 +/- 14.7%, p = 0.03). Thrombolysis was significantly higher after 15 min of ultrasound exposure (12.8 +/- 9.1% in the ultrasound-treated group 2 vs. 4.0 +/- 3.9% in group 3, p < 0.05). The maximal difference between groups 2 and 3 occurred at 25 min (26.7 +/- 13.1% vs. 7.24 +/- 5.7%, p < 0.004). Neither flow nor clot lysis occurred in group 1. Plasminogen and fibrinogen concentrations and rt-PA antigen concentrations were consistent with those observed during fibrinolytic therapy in vivo. CONCLUSIONS: Continuous wave ultrasound at 0.5 MHz and an intensity of 8 W/cm2 accelerates rt-PA-induced thrombolysis and reperfusion in vitro.

Blood Flow Velocity↗
PubMed1993

Reversible catecholamine-induced cardiomyopathy presenting as acute pulmonary edema in a patient with pheochromocytoma.

Cardiac injury caused by elevated levels of circulating catecholamines is a well-known phenomenon. We report a patient who, secondary to transient regional left ventricular dysfunction (despite normal coronary arteries), developed acute pulmonary edema. Echocardiography showed marked anteroapical hypokinesia and an apical thrombus. The diagnosis of pheochromocytoma was made by plasma catecholamine levels, abdominal ultrasound and finally at operation. The patient recovered completely long before surgical intervention was undertaken.

Adrenal Gland Neoplasms↗
PubMed1993

Ventricular septal rupture after myocardial infarction. Detection by transesophageal echocardiography.

Acute rupture of the interventricular septum is a relatively unusual complication following acute myocardial infarction. The echocardiographic features depicted by transthoracic echocardiography are well described. However, transesophageal echocardiographic description of a ruptured septum has not been previously reported. This brief report illustrates the transesophageal features of such a defect.

Aged↗
PubMed1987

X-ray microanalysis of the fingernails in cirrhotic patients.

The element content of clipped nails of 13 patients with liver cirrhosis was examined by X-ray microanalysis, and compared with that of 50 healthy subjects. The results showed a statistically significant increase in the percentage of Na, Mg and P and a slight, but statistically significant decrease in S and Cl. The percentage of K, Ca, Fe, Cu and Zn did not show any difference from that of the controls. The findings indicate that X-ray microanalysis may be a valuable tool for the simultaneous examination of a large number of elements in the fingernails.

Aged↗
PubMedDate not supplied

Right-to-left shunt through a patent foramen ovale caused by severe tricuspid regurgitation detected with color Doppler echocardiography.

We describe a 65-year-old patient with moderate combined mitral disease and severe tricuspid regurgitation, in whom the tricuspid regurgitant jet was oriented toward the interatrial septum. Color flow and pulsed Doppler demonstrated a late-systolic to mid-diastolic, right-to-left shunting of the tricuspid regurgitant jet through the foramen ovale. This finding was subsequently confirmed with transesophageal echocardiography.

Aged↗
PubMedDate not supplied

Transesophageal echocardiographic recognition of an unusual complication of aortic valve endocarditis.

Aortic valve endocarditis can cause complications due to involvement of the subaortic structures. These complications include satellite vegetations on the aortic regurgitant jet lesion sites, involvement of the anterior or posterior mitral valve leaflets in the form of aneurysms, perforation, and involvement of the mitral-aortic intervalvular fibrosa, namely abscess, aneurysm, and perforation into the left atrium or the pericardial sac. These complications can be identified accurately by echocardiography. We report an unusual case which demonstrates (1) coexistence of both mitral-aortic intervalvular fibrosa and mitral valve aneurysms, and (2) echocardiographic follow-up of a mitral valve aneurysm to perforation. These complications were recognized by transesophageal echocardiography and verified at surgery.

Adult↗
PubMedDate not supplied

Ventricular aneurysm repair: a new approach.

Repair of chronic left ventricular aneurysm or acute rupture of the heart after myocardial infarction is associated with technical difficulties and major morbidity and mortality. We describe a new endoventricular repair for both conditions. The repair consists of externally covering a Duran ring with Dacron and internally lining it with autologous pericardium. The modified ring is then sewn into the neck of the lesion. The technique is rapid, simple, and hemostatic. After repair of the chronic aneurysm, ventricular hemodynamics are improved during both diastole and systole. We have performed this technique in two patients with chronic aneurysm and one with subacute rupture.

Adult↗