Search PubMed⌕ Search

Biomedical subjects

E Kaplinsky

Publications and source records attributed to E Kaplinsky.

204 records · Page 12Linked to original sources
PubMedDate not supplied

Quantitative myocardial ultrasonic integrated backscatter measurements during contrast injections.

We and others have shown that normal myocardium exhibits 4 to 5 dB diastolic-to-systolic cyclic variation (CV) of integrated backscatter. To investigate the effect of intramyocardial contrast on integrated backscatter, we injected 5% sonicated albumin, containing microbubbles in the range of 5 microns in diameter, into the left atrium in nine open-chest dogs. The dogs were anesthetized and placed in the right lateral decubitus position on a specially designed table with a cutout allowing ultrasound imaging from below. Ultrasonic data was obtained from the right precordium by use of a prototype M-mode integrated backscatter system implemented in a commercially available two-dimensional system. Usable data were obtained in eight of nine dogs. Integrated backscatter increased up to 13 dB after contrast injections. There was a significantly decreased CV of integrated backscatter during myocardial contrast in all eight dogs. The mean level of CV of integrated backscatter for the eight dogs decreased from 4.7 dB (530 beats analyzed) without contrast to 2.8 dB during contrast (436 beats analyzed). There was a trend to greater CV at higher levels of contrast. Septal excursion, as measured by M-mode echocardiography simultaneously with integrated backscatter by the same ultrasound beam, was similar with and without contrast (mean 8.2 vs 8.3 mm). Thus left atrium contrast injection produces quantitatively measurable integrated backscatter effects. Cyclic variation of integrated backscatter decreases with contrast. However, at higher contrast levels the decrease tends to be smaller. These effects should be considered during quantitative tissue characterization and myocardial contrast studies.

Albumins↗
PubMedDate not supplied

Echocardiographic left ventricular remodeling and pseudohypertrophy as markers of hypovolemia. An experimental study on bleeding and volume repletion.

BACKGROUND: Monitoring intravascular volume during surgery, especially in major cardiovascular procedures is necessary for appropriate fluid restoration and the maintenance of an adequate cardiac output. In estimating preload, both standard hemodynamic and echocardiographic parameters have been limited. The purpose of this study was to further define the effects of induced hypovolemia on the echocardiographic parameters. In particular, we sought to show whether a decrease in echocardiographic left ventricular area and volume was associated with a significant increase in left ventricular wall thickness (left ventricular pseudohypertrophy) and with changes in LV function. In addition, we sought to investigate the effects of rapid restoration of blood volume on cardiac dimensions and function. METHODS AND RESULTS: Seven anesthetized pigs underwent systemic and right heart pressures and cardiac output measurements. Two-dimensional echocardiographic parasternal long- and short-axis views were obtained during graded bleeding by rapid withdrawal of blood from an arterial cannula, with increments of 5% each up to 30% of calculated blood volume. After completion of the bleeding, the entire amount of the blood withdrawn was retransfused within 4 to 5 minutes. Both hemodynamic and echocardiographic measurements were performed at baseline, immediately after the completion of each stage of bleeding and after blood restoration. Mean (+/- standard deviation) left ventricular wall thickness (mean of septal and posterior wall thickness) was 6.3 +/- 0.1 mm at baseline, 8.3 +/- 1.5 mm at peak bleeding, and 6.2 +/- 0.1 after restoration (p < 0.01). Left ventricular mass did not change during the experiment. Left ventricular end-diastolic volume was 62.8 +/- 20.3 ml at baseline, 37.5 +/- 12.4 ml at peak bleeding (p < 0.0001), and 65.9 +/- 16.7 ml after blood restoration (p < 0.001 compared with 30% bleeding). H/r ratio (posterior wall thickness divided by left ventricular radius) increased from 0.29 +/- 0.07 at baseline to 0.50 +/- 0.19 at peak bleeding returning to 0.26 +/- 0.04 after restoration. Left ventricular ejection fraction was 0.53 +/- 0.10 at baseline and 0.55 +/- 0.20 at peak bleeding (not significant), decreasing to 0.38 +/- 0.11 after blood restoration (p < 0.05 compared with 30% bleeding). End-diastolic volume correlated closely with right atrial pressure (r = -0.82), capillary wedge pressure (r = -0.78), and stroke volume (r = 0.74). Left ventricular ejection fraction inversely correlated with left ventricular end-diastolic volume (r = -0.48) and with end-systolic wall stress (r = -0.62). The changes in interventricular septal and posterior wall thickness were inversely related to left ventricular end-diastolic volume (r = -0.72 and -0.35, respectively). CONCLUSIONS: This study shows that transient concentric left ventricular remodeling (pseudohypertrophy), a phenomenon previously described in cardiac tamponade and during rapid atrial pacing is commonly seen during hypovolemia. This new sign may further enhance the echocardiographic estimation of left ventricular preload.

Animals↗
PubMedDate not supplied

Prostaglandin E1 during angioplasty as preventative therapy for coronary restenosis.

The effect of intravenous prostaglandin E ( 1 ) (PGE ( 1 ) ) on the incidence of restenosis after elective percutaneous transluminal coronary angioplasty (PTCA) was studied in a prospective, single-blind, randomized trial of 30 patients. Group I (12 patients) received only the conventional medications before and after protocol, and group II (18 patients) received intravenous PGE ( 1 ) infusion for 24 hours starting at least 2 hours before angiography after hemodynamically based titration to a mean dosage of 16 +/- 3 ng/kg/min (range, 10-20 ng/kg/min). All patients received aspirin orally, beginning 24 hours before PTCA and continuing for 6 months, and intravenous heparin at 1000 U/h for 24 hours commencing with the beginning of catheterization before PTCA. Recatheterization was performed routinely at 6 months after PTCA, or earlier when clinically indicated. Angiographic evaluations were made by both visual and quantitative assessment. No significant side effects of PGE ( 1 ) treatment were observed. Only 17% of patients treated by PGE ( 1 ) experienced angina pectoris during 6-month follow-up period, as compared with 42% of patients who received conventional treatment (p = 0.13). Re-PTCA was more frequent in patients receiving conventional therapy than in those receiving PGE ( 1 ) (42% versus 11%; p = 0.06). The use of PGE ( 1 ) during PTCA was associated with 17% restenosis (both by computer and by visual evaluation) 6 months post-PTCA as compared with 33% and 50% restenosis (by computer and by visual evaluations, respectively) in the conventional group (p < 0.05). In conclusion, PGE ( 1 ) appears to decrease coronary restenosis 6 months after PTCA.

Adult↗
PubMedDate not supplied

Effects of antegrade versus combined antegrade/retrograde cardioplegia on postoperative septal wall motion in patients undergoing open heart surgery.

To evaluate the influence of two techniques of myocardial protection on septal wall motion (SWM) and left ventricular ejection fraction, 21 patients with a normal SWM underwent surgery using either conventional antegrade cardioplegia (group I, n = 9) or combined antegrade/retrograde cardioplegia (group II, n = 12). The patients were assessed pre- and postoperatively by radionuclide ventriculography. A resting thallium-201 study was performed in patients (n = 6) with a postoperatively abnormal SWM: in 2 of 9 (22%) in group I and in 4 of 12 (33%) in group II (p = NS). The left ventricular ejection fraction was similar in both groups before surgery (57 +/- 3% in group I vs. 57 +/- 8% in group II; p = NS) and did not change significantly after surgery. All 6 patients with an abnormal SWM had a normal septal thallium-201 uptake. Thus, (1) an abnormal SWM after cardiac surgery is common: (2) it is not due to perioperative ischemia or infarction, and (3) neither the incidence of an abnormal SWM not the global left ventricular function is influenced by the addition of retrograde cardioplegia during open heart surgery.

Adult↗
PubMedDate not supplied

Unusual congenital coronary arterio-venous fistulae with surgical correction.

A typical case of anginal syndrome in a fifty year old male has been described. The underlying lesion was congenital coronary arterio-venous fistula between the left anterior descending branch of the left coronary artery and pulmonary artery. Diagnosis has been made by coronary angiography and proved at operation. The patient underwent successful operation where a multiple fistulous ostia draining into the pulmonary trunk were obliterated by means of extracorporeal circulation. The pertinent literature related to this congenital anomaly and symptomatology has been reviewed.

Angina Pectoris↗