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Biomedical subjects

C Pollick

Publications and source records attributed to C Pollick.

At least 37 records · Page 2Linked to original sources
PubMed1989

Mitral valve annuloplasty: the effect of the type on left ventricular function.

This study was undertaken to determine whether rigid-ring annuloplasty and flexible-ring annuloplasty have the same effect on left ventricular function in patients with chronic mitral regurgitation secondary to degenerative disease of the mitral valve. Twenty-five patients who underwent isolated mitral valve repair and required annuloplasty were randomized into two groups: rigid-ring and flexible-ring annuloplasty. Left ventricular function was assessed by echocardiography and radionuclide angiography on the day before operation and 2 to 3 months later. Preoperative left ventricular function was similar in the two groups of patients. Postoperatively, left ventricular end-diastolic diameter and volume decreased significantly in both groups. The left ventricular end-systolic diameter and volume decreased significantly only in patients with a flexible annuloplasty ring. Left ventricular systolic function as assessed by pressure-volume relationships was significantly better in patients with a flexible ring (p less than 0.02 by analysis of covariance), and left ventricular performance measured by stroke volume-end-diastolic volume relationships was also better in these patients (p less than 0.05 by analysis of covariance). These data indicate that patients with a flexible annuloplasty ring have better left ventricular systolic function than patients with a rigid annuloplasty ring 2 to 3 months after mitral valve reconstruction for chronic mitral regurgitation secondary to degenerative disease of the mitral valve.

Adult↗
PubMed1989

Acute myocarditis presenting as asymmetric septal hypertrophy.

A 19-year-old male with myocarditis presented with the echocardiographic appearance of asymmetric septal hypertrophy. After six days of steroid therapy the septum and the posterior wall returned to normal thickness. This case suggests that a diagnosis of myocarditis should be considered in patients demonstrating asymmetric septal hypertrophy, particularly when there are associated left ventricular wall motion abnormalities.

Adult↗
PubMed1988

Disopyramide in hypertrophic cardiomyopathy. I. Hemodynamic assessment after intravenous administration.

The hemodynamic effects of intravenous disopyramide were determined in 43 patients with hypertrophic cardiomyopathy and pressure gradients at rest (resting obstruction). The basal subaortic pressure gradient decreased in all patients by a mean of 61 mm Hg (range 16 to 123); in 35 patients the gradient was abolished (less than 20 mm Hg). The reduction in pressure gradient was achieved through a decrease in left ventricular systolic pressure, from 178 to 135 mm Hg (p less than 0.0001), and a rise in aortic systolic pressure, from 105 to 123 mm Hg (p less than 0.0001). Left ventricular ejection time was reduced from 326 to 273 ms (p less than 0.0001). Left ventricular end-diastolic pressure decreased from 19 to 16 mm Hg (p less than 0.0001). In a subgroup of 13 patients, cardiac output was unchanged after disopyramide, despite a prolongation of the pre-ejection period from 104 to 137 ms (p less than 0.0001) indicating a decrease in contractility. The maintenance of cardiac output, despite a decrease in contractility, may reflect a decrease in mitral regurgitation resulting from the reduction of systolic anterior motion of the mitral valve by disopyramide. These results indicate that disopyramide produces predictably favorable hemodynamic effects in patients with hypertrophic cardiomyopathy and resting obstruction to left ventricular outflow.

Adolescent↗
PubMed1988

Disopyramide in hypertrophic cardiomyopathy. II. Noninvasive assessment after oral administration.

The effects of oral disopyramide 150 mg 4 times a day were compared with propranolol 40 mg 4 times a day and placebo in 10 patients with hypertrophic cardiomyopathy and resting obstruction (7 patients) or latent obstruction (3 patients), in a randomized double-blind crossover design; each drug was given for a period of 4 days. As determined from echocardiographic evaluation of systolic anterior motion of the mitral valve, the subaortic pressure gradient was decreased from 61 +/- 20 mm Hg with placebo to 5 +/- 15 mm Hg with disopyramide (p less than 0.01), and 30 +/- 30 mm Hg with propranolol (p less than 0.01). Disopyramide was more effective than propranolol (p less than 0.01). Disopyramide and propranolol both shortened left ventricular ejection time from 352 +/- 51 ms with placebo to 314 +/- 26 and 322 +/- 41 ms, respectively (p less than 0.01). Preejection period was lengthened from 93 +/- 35 ms with placebo to 119 +/- 25 ms with disopyramide, but was unchanged by propranolol at 98 +/- 23 ms. Disopyramide increased exercise duration versus placebo (10.4 +/- 2 vs 9.6 +/- 2 minutes, respectively (p less than 0.05), whereas propranolol produced no significant change (8.8 +/- 2 minutes).

Administration, Oral↗
PubMed1988

Left ventricular wall motion abnormalities in subarachnoid hemorrhage: an echocardiographic study.

Although electrocardiographic (ECG) abnormalities and autopsy evidence of myocardial necrosis are associated with subarachnoid hemorrhage, their relation to in vivo measures of left ventricular function in this condition has not been established. Thirteen patients with subarachnoid hemorrhage and no prior history of heart disease were studied by two-dimensional echocardiography, performed initially 10 to 48 h (mean 18) after admission and serially for less than or equal to 14 days. Serum creatine kinase (total and myocardial isoenzyme) was determined 5 times over the first 48 h; ECGs were performed daily. Neurologic state was assessed with the use of a standard grading system. Four patients (Group I) exhibited left ventricular wall motion abnormalities in one to eight segments. In two of these patients there was also left ventricular apical mural thrombus that embolized in one patient, leading to further neurologic deterioration. The initial creatine kinase myocardial isoenzyme was higher in Group I than in Group II (patients without wall motion abnormalities) (10.3 versus 2.1 U/liter, p less than 0.001), initial heart rate was higher (91 versus 61 beats/min, p less than 0.01), neurologic grade was higher (2.5 to 4.5 versus 1 to 2, p less than 0.001) and inverted T waves were more common (4 of 4 versus 1 of 9). Three of the four patients in Group I died; two of the three underwent autopsy and were found to have no significant coronary artery disease. No other patients died.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Doppler color-flow imaging assessment of shunt size in atrial septal defect.

Two-dimensional echocardiography and pulsed-Doppler studies have not proved to be reliable methods of assessing left-to-right shunt size in atrial septal defect. Doppler color-flow imaging displays the transatrial jet, providing a new dimension with the potential capability of quantifying left-to-right shunt size. Twenty-three patients with atrial septal defect were studied by color-flow imaging and cardiac catheterization. The defect size measured by two-dimensional echocardiography, the maximal color-flow jet width in the atrial septum, and the maximal color-flow jet area in the right atrium were correlated with cardiac catheterization-derived left-to-right shunt size. Correlation coefficients were 0.57 (p less than 0.01), 0.67 (p less than 0.001), and 0.65 (p less than 0.01), respectively. Atrial septal color-flow jet width distinguished patients with less than a 2:1 left-to-right shunt size ratio (eight patients, jet width less than 15 mm in in all) from patients with greater than a 2:1 left-to-right shunt size ratio (15 patients, jet width greater than 15 mm in all). These results indicate that Doppler color-flow imaging can distinguish left-to-right shunt size in atrial septal defect accurately enough to influence decisions with regard to subsequent patient management.

Adult↗
PubMed1988

Colour flow imaging in severe mitral and aortic regurgitation.

Several criteria have been proposed for the grading of severe aortic and mitral regurgitation by colour flow imaging. To evaluate the sensitivity of these criteria, colour flow imaging was performed in 21 patients with isolated severe mitral regurgitation and 11 patients with isolated severe aortic regurgitation prior to clinically indicated valvular surgery. In the colour flow imaging assessment of mitral regurgitation the criterion of the maximum distance of mitral regurgitant jet from mitral orifice greater than 4.5 cm was 95% sensitive (range 4.4 to 8.4 cm). Maximum ratio of mitral regurgitant jet area to left atrial area greater than 40% was 86% sensitive (range 32 to 84%) and maximum mitral regurgitant jet area greater than 6 cm2 was 100% sensitive (range 8.1 to 35.7 cm2) in the detection of severe mitral regurgitation. For aortic regurgitation, the criterion of height of regurgitant jet to height of left ventricular outflow tract greater than 65% in the parasternal long axis view was 100% sensitive (range 71 to 100%), whereas the ratio of area of regurgitant jet to area of left ventricular outflow tract greater than 60% in the short axis view was only 36% sensitive (range 8 to 74%) in the detection of severe aortic regurgitation requiring surgery. It is concluded that the most sensitive colour flow imaging criteria for severe mitral regurgitation is an absolute mitral jet area greater than 8 cm2; and for severe aortic regurgitation, ratio of height of regurgitant jet to height of left ventricular outflow tract greater than 65%.

Adult↗
PubMed1985

Unlocking the mystery of systolic anterior motion: the key is timing.

Though a generation has elapsed since the recognition of hypertrophic cardiomyopathy, controversy continues to rage regarding its pathophysiology. Central to the controversy is the mechanism and significance of the pressure gradient. Systolic anterior motion (SAM) of the mitral valve, as demonstrated by angiography and echocardiography, is accepted as the cause of the pressure gradient by some groups but not others. The latter authors suggest that: SAM is an incidental effect of vigorous contraction which is itself the cause of the pressure gradient and that the pressure gradient does not represent left ventricular outflow obstruction. These views are examined in light of recent studies that have assessed the temporal and quantitative relationship between SAM and the pressure gradient. It is concluded that SAM with early mitral septal contact is the cause of the pressure gradient, and represents true left ventricular outflow obstruction.

Blood Flow Velocity↗
PubMed1984

Muscular subaortic stenosis: the quantitative relationship between systolic anterior motion and the pressure gradient.

We performed simultaneous echocardiographic and hemodynamic studies in 11 patients with muscular subaortic stenosis to determine whether systolic anterior motion (SAM) of the anterior mitral leaflet and the pressure gradient are related quantitatively. SAM without septal contact was associated with either no gradient or a small impulse gradient of less than 10 mm Hg. SAM with septal contact was always associated with a pressure gradient of more than 10 mm Hg. The size of the pressure gradient correlated inversely with the time periods: (1) onset of SAM-septal contact (r = .79, p less than .001) and (2) onset of aortic ejection to onset of SAM-septal contact (r = -.89, p less than .001). Size also correlated directly with the time period: (3) duration of SAM-septal contact (r = .80, p less than .001). Thus when the time from the onset of SAM to the onset of SAM-septal contact was long, SAM-septal contact developed late in systole, the duration of SAM-septal contact was brief and the pressure gradient was low. When SAM-septal contact developed in early systole, the duration of SAM-septal contact was long and the pressure gradient was high. With the index of time period (3) divided by time period (1), a regression equation was devised to predict the size of the pressure gradient (pressure gradient [mm Hg] = 25 [ratio] + 25; r = .90, p less than .001; SE +/- 15 mm Hg). The echocardiographic time period index was validated prospectively in nine other patients and the significant correlation with the hemodynamically determined gradient persisted (r = .89, p less than .01). We conclude that SAM and the pressure gradient are related quantitatively in muscular subaortic stenosis. These observations have implications regarding the mechanism and significance of the pressure gradient in muscular subaortic stenosis.

Adult↗
PubMed1983

Variability of digitized echocardiography: size, source, and means of reduction.

Digitization of M-mode echocardiograms provides useful information on left ventricular function, but its variability has been assessed rarely. Inter- and intraobserver (technical) variability of readers digitizing the same cardiac cycles, and variability between beats, days, and subjects (biologic) was determined. Technical variability was small for both standard dimensions (correlation coefficient r values 0.82 to 1.00) and rates of change (r values 0.70 to 0.98). Biologic variability was large with expected normal differences between 2 measurements (95% confidence limits) of 11 to 55% and 37 to 106% for standard dimensions and rates of change, respectively. By averaging measurements of 5 beats from each of 2 days, the expected normal differences are reduced to 6 to 32% and 23 to 63% for standard dimensions and rates of change. This study emphasizes the large biologic variability in rates of change of digitized left ventricular measurements. Normal variation between studies can be reduced and real physiologic or pathologic changes perceived best if many beats from more than 1 day are measured.

Adult↗
PubMed1982

Mitral and aortic valve orifice area in normal subjects and in patients with congestive cardiomyopathy: determination by two dimensional echocardiography.

Previous determinations of normal valve orifice areas have been mainly from postmortem studies. In this study mitral and aortic valve orifice area were determined from two dimensional echocardiograms in 20 normal subjects and 20 patients with congestive cardiomyopathy. Mitral valve orifice area was larger than quoted in standard textbooks. Both mitral and aortic valve orifice area were reduced in patients with cardiomyopathy. Valve opening was assessed relative to left ventricular and aortic root size. The ratio of mitral valve orifice area to left ventricular cross-sectional area was markedly reduced in patients with cardiomyopathy compared with normal subjects. The ratio of aortic valve orifice area to aortic root size also was reduced in patients with cardiomyopathy. Anterior mitral leaflet E point-septal separation was similar to that in previous reports contrasting normal subjects with patients with myopathy. Among patients with cardiomyopathy, mitral E point-septal separation was primarily a function of left ventricular size and was not significantly correlated with fractional shortening or ejection fraction within this group having uniformly poor systolic function.

Adolescent↗
PubMed1982

Cardiovascular physiology in a case of heterotopic cardiac transplantation.

Successful heterotopic cardiac transplantation in a 24 year old man with end stage cardiomyopathy provided an opportunity to study cardiovascular physiology. The donor and native hearts, functioning independently in parallel, were studied by serial physical examination, electrocardiography, echocardiography, nuclear angiography and cardiac catheterization. Results indicated that the donor left heart assumed the predominant role in supplying systemic output, possibly contributing to decreasing function of the patient's own (native) heart. Analysis of serial nuclear angiograms revealed an initial postoperative ejection fraction of 52 and 21 percent in the donor and the native left ventricle, respectively; repeat studies 3 months postoperatively showed values of 50 and 9 percent, respectively, indicating significant deterioration in native left ventricular cardiac function. Observation of valve motion of the native heart showed major irregularities of the aortic valve in contrast to seemingly normal, regular mitral valve motion. These data rise interesting questions regarding interpretation of valve motion as an indicator of ventricular function.

Adult↗
PubMed1982

The cardiac effects of d- and l-disopyramide in normal subjects: a noninvasive study.

Commercially available disopyramide is a racemic mixture of equal parts of dextrorotatory (d-) and levorotatory (l-) optical isomers. We studied the cardiac effects of i.v. administration of each isomer and the racemic mixture (dl-) in six normal males by digitized echocardiography, systolic time intervals and ECG. Both isomers and the racemic mixture produced equally marked dose-dependent negative inotropic effects (28.1 +/- 11.8% mean maximal reduction in fractional shortening of left ventricular dimension) and diastolic effects (28.6 +/- 24.1% mean maximal reduction in peak left ventricular filling rate). However, only the d-isomer prolonged QTc duration (by 13.6 +/- 5.2% at maximum, p less than 0.001 vs l-isomer). We conclude that disopyramide, in the doses used, produces marked adverse effects on left ventricle systolic and diastolic function in normal subjects independent of optical rotation. The production of these effects by the l-isomer without affecting QTc duration suggests different subcellular mechanisms for the myocardial depressant effects and some of the electrophysiologic effects of disopyramide.

Adult↗