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Biomedical subjects

H Rakowski

Publications and source records attributed to H Rakowski.

At least 55 records · Page 3Linked to original sources
PubMed1991

Mitral valve repair by replacement of chordae tendineae with polytetrafluoroethylene sutures.

Expanded polytetrafluoroethylene sutures have been used for replacement of diseased chordae tendineae during reconstructive procedures on the mitral valve in 43 patients. There were 28 men and 15 women whose mean age was 55 years, range 21 to 76. Three fourths of the patients were in New York Heart Association class III or IV. Replacement of primary chordae tendineae of the anterior leaflet was performed with 4-0 or 5-0 polytetrafluoroethylene sutures. A double-armed suture was passed twice through the fibrous portion of the papillary muscle head and tied down. Each arm of the suture was brought up to the free margin of the leaflet and passed through the area where the native chorda was attached. After the lengths of the two arms were adjusted, the ends were tied together on the ventricular side of the leaflet. Thirty patients had degenerative disease of the mitral valve; the incompetence was due to prolapse of the anterior leaflet in 14 patients and prolapse of the anterior and posterior leaflets in 16. Eleven patients had rheumatic mitral valve disease: four had stenosis, three had regurgitation, and four had mixed lesions. Two patients had ischemic mitral regurgitation caused by rupture of a papillary muscle head. There were no operative deaths. Patients have been followed up from 5 to 61 months, mean 13. Doppler echocardiographic studies were performed at regular intervals after the operation and revealed normal mitral valve function in most patients There were two failures that necessitated mitral valve replacement: one because of acute mitral regurgitation and the other because of hemolysis. There have been two late deaths, neither one valve related. Replacement of chordae tendineae with polytetrafluoroethylene sutures is simple and allows for reconstruction of the mitral valve in many patients who would otherwise require mitral valve replacement. Because our patients have been followed up for a limited time, the long-term results of this procedure remain unknown.

Chordae Tendineae↗
PubMed1990

Apical hypertrophic cardiomyopathy: clinical follow-up and diagnostic correlates.

To determine the clinical course of apical hypertrophic cardiomyopathy, 26 patients (mean age 45 years) with asymmetric apical hypertrophy diagnosed by echocardiography or angiography were followed up for an average of 7.3 years (range 1 to 22). Presenting symptoms included atypical chest pain (n = 10), typical angina (n = 6), dyspnea (n = 5) and palpitation (n = 8). Ten patients were asymptomatic. At follow-up all patients had inverted precordial T waves, and 14 had the syndrome of "giant T wave negativity" (greater than or equal to 10 mm). In six patients with electrocardiographic follow-up of greater than 10 years (mean 13.4), precordial T wave inversion had progressed from -0.8 +/- 3.9 to -11.2 +/- 8.0 mm in lead V4 in association with increased QRS amplitude. Episodic atrial fibrillation occurred in 4 of 10 patients with echocardiographic left atrial enlargement. Although left ventricular systolic function was normal, diastolic relaxation was impaired in comparison with values in 10 healthy control subjects: in all 18 patients studied peak filling rate was decreased (4.44 +/- 0.44 versus 6.13 +/- 1.54 stroke volumes/s); time to peak filling was increased (174 +/- 40 versus 147 +/- 32 ms); and atrial systolic contribution to ventricular end-diastolic volume was increased (21.5 +/- 6.8 versus 11.5 +/- 4.6 stroke volume %). During follow-up, 21 of the 26 patients remained in stable condition or were asymptomatic. One patient with normal coronary arteries had an apical myocardial infarction with development of a discrete apical aneurysm and loss of "giant T wave negativity." This patient was the only one to have documented life-threatening ventricular arrhythmias.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗
PubMed1990

Comparison of transthoracic and transesophageal assessment of prosthetic valve dysfunction.

Transesophageal echocardiography has added another dimension to the assessment of prosthetic valve dysfunction with high-resolution images that allow for more detailed structural evaluation of tissue and mechanical valves. This study is a retrospective analysis of 140 prosthetic valves (90 tissue, 50 mechanical) in the mitral (89), aortic (45), and tricuspid (6) position in 116 patients studied by transthoracic and transesophageal echocardiography techniques. Transesophageal echocardiography was consistently better than the transthoracic technique in the evaluation of structural abnormalities of tissue valves in the mitral and aortic positions with respect to leaflet thickening, prolapse, flail, and vegetations. With transesophageal echocardiography, five tissue mitral valves had flail leaflets that were not identified by the transthoracic technique. Transesophageal echocardiography was better than transthoracic in the detection, quantification, and localization of prosthetic mitral regurgitation. Physiological mitral regurgitation was detected in 31 valves by transesophageal echocardiography compared to seven by transthoracic technique. By transesophageal echocardiography, mitral regurgitation was paravalvular in 24% compared with 4% by transthoracic technique. Left atrial spontaneous contrast was seen in 42% of the patients with a mitral prosthesis detected only by transesophageal echocardiography. Six patients had left atrial or left atrial appendage thrombus and in five patients they were detected only by transesophageal echocardiography. We conclude that transesophageal echocardiography should be a complimentary test to transthoracic studies in patients with suspected prosthetic valve dysfunction or for the follow-up of older tissue valves.

Adult↗
PubMed1990

Doppler echocardiography assessment of prosthetic heart valves.

Transthoracic Doppler echocardiography is an accurate noninvasive method for the evaluation of prosthetic valve function. The flow characteristics and pressure gradients of normally functioning mechanical and bioprosthetic valves have been, in general established. Normal functioning mitral valve prostheses have a valve area greater than 1.8 cm 2 with the St. Jude valve having the largest effective valve area and normally functioning aortic prosthetic valves have a peak instantaneous gradient of less than 45 mmHg, with the Starr-Edwards valves (Starr-Edwards, Irvine CA) showing the highest gradients. The incidence of minimal or mild regurgitation is approximately 15% to 30% in the mitral position and 25% to 50% in the aortic position, with the higher incidence of regurgitation seen with mechanical compared to bioprosthetic valves. Transthoracic Doppler echocardiography can accurately detect patients with prosthetic valvular stenosis. The presence of prosthetic aortic regurgitation can also generally be accurately assessed, except in the presence of both prosthetic aortic and mitral valves. Assessment of prosthetic mitral regurgitation remains limited due to significant attenuation of the ultrasound beam by the prosthesis and the frequent underestimation of severity of regurgitation. Other limitations of transthoracic studies include assessment of leaflet morphology, detection of vegetations and valve abscesses, and differentiation between valvular and paravalvular regurgitation.

Bioprosthesis↗
PubMed1990

Echocardiographic and Doppler studies in hypertrophic cardiomyopathy.

This article discusses the central role of cardiac ultrasonography-- two dimensional echocardiography, Doppler echocardiography, continuous-wave Doppler, pulsed-wave Doppler--in the clinical assessment and management of patients with hypertrophic cardiomyopathy.

Cardiomyopathy, Hypertrophic↗
PubMed1990

Clinical and Doppler echocardiographic evaluation of bioprosthetic valve failure after 10 years.

Four hundred thirteen consecutive patients underwent valve replacement with a bioprosthesis between 1976 and 1982. Aortic valve replacement was performed in 240 patients, mitral valve replacement in 132 patients, and multiple valve replacement in 41. The Carpentier-Edwards porcine (n = 336), Angell-Shiley porcine (n = 23), Hancock porcine (n = 11), and the Ionescu-Shiley pericardial valves (n = 43) were inserted. Follow-up between 5 and 12 years postoperatively was 98% complete. Freedom from structural valve deterioration was 72 +/- 7%, 59 +/- 9%, and 59 +/- 9%, respectively, after aortic, mitral, and double valve replacement. The risk of structural valve deterioration and reoperation for valve-related complications was significantly increased with the Ionescu-Shiley pericardial prosthesis. The risk for reoperation was inversely related to patient age. Postoperative Doppler echocardiographic studies in 87% of available patients revealed a subgroup of asymptomatic patients with evidence of structural valve deterioration. These patients (n = 61) had significantly reduced prosthetic valve areas (aortic less than 1 cm2, mitral less than 1.7 cm2), elevated resting transvalvular gradients (aortic greater than 40 mm Hg), or moderate-to-severe regurgitation. In summary, postoperative Doppler echocardiographic examination identified asymptomatic patients with structural valve dysfunction. These patients must be followed up carefully to determine the optimal timing of reoperation.

Aortic Valve↗
PubMed1989

Recovery of elevated atrial natriuretic peptide in pressure-overload right heart failure.

Elevation of the plasma concentrations of immunoreactive atrial natriuretic peptide (ANP) was observed in canine chronic right heart failure (RHF) secondary to right ventricular (RV) pressure overload. Pressure overload on the right heart was gradually increased using an inflatable cuff. The interval between banding and the onset of RHF was 152 +/- 52 days. Seventeen RHF dogs were produced and divided into Group I (n = 11) and Group II (n = 6). At the onset of RHF, Group I dogs were either sacrificed for study of the heart, or unbanded to allow recovery from RHF. The dogs in Group II were maintained in RHF for 3 additional months before being either sacrificed or unbanded. Following unbanding, the ANP level of Group I recovered from 108 +/- 36 (n = 11) to 20 +/- 6 pg/ml (n = 6) at 1 month and was maintained at 27 +/- 7 pg/ml (baseline, 21 +/- 5 pg/ml, n = 11) at 4 months. ANP levels of Group II declined from 165 +/- 55 (n = 6) to 87 +/- 2 pg/ml (n = 3) at 1 month and further decreased to 42 +/- 14 pg/ml (n = 3) 4 months after unbanding. Thus, compared to Group I, Group II had a high ANP level before unbanding and a delay in recovery of the ANP levels despite normalization of the right atrial pressure (RAP). Four months after release of pressure overload, the right atrial hypertrophy persisted in the unbanded dogs; however, Group I unbanded dogs showed a better reversal of the right atrial hypertrophy than Group II unbanded dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Causal relation between the pressure gradient and left ventricular ejection time in hypertrophic cardiomyopathy.

This study was designed to evaluate the relation between severity of obstruction to left ventricular outflow and left ventricular ejection time in hypertrophic obstructive cardiomyopathy. With dual catheters across the left ventricular outflow tract, the pressure gradient and corresponding left ventricular ejection time were measured in 10 patients as the pressure gradient was pharmacologically provoked or abolished, or both. The patients were studied during constant atrial pacing to avoid the potential errors introduced with heart rate correction equations. The pressure gradient was pharmacologically provoked or reduced over a range of greater than or equal to 62 mm Hg per patient. In each patient the left ventricular ejection time varied directly with the pressure gradient (mean r = 0.97, range 0.92 to 1.00). The change in magnitude of the pressure gradient varied directly with the corresponding change in the measured ejection time (mean r = 0.98, range 0.97 to 1.00). When the data from all 10 patients were pooled with use of Weissler's heart rate correction equation, the relation between the corrected left ventricular ejection time and the pressure gradient was still significant and linear (r = 0.86), but less so than in individual patients. This difference was the result of marked interpatient variability in the slope of this linear relation reflecting interpatient differences in other important factors, such as underlying myocardial contractility and stroke volume, that influence left ventricular ejection time. This study demonstrates a clear, direct and highly significant relation between the magnitude of the pressure gradient and the left ventricular ejection time in hypertrophic obstructive cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1989

Aortic regurgitation: a common complication after surgery for hypertrophic obstructive cardiomyopathy.

Surgical ventriculomyectomy and ventriculomyotomy by the aortic approach are safe and effective methods of relieving symptoms and obstruction to left ventricular outflow in patients with hypertrophic obstructive cardiomyopathy. With the addition of Doppler ultrasound to the routine follow-up assessment of these patients an unexpectedly high occurrence of aortic regurgitation was found in the postoperative patients. Because aortic regurgitation has been reported to rarely accompany this condition, 67 patients with hypertrophic obstructive cardiomyopathy were studied clinically and with Doppler echocardiography for the presence and severity of aortic regurgitation. Severity of the regurgitation was quantitated by pulsed or color Doppler echocardiography according to the length and width of the regurgitant jet in at least two views. In 37 patients with hypertrophic obstructive cardiomyopathy who did not undergo surgery, aortic regurgitation was detected in only 1 (3%) by Doppler ultrasound and in none clinically. In 52 patients who did undergo surgery and were studied a mean of 7.8 years postoperatively, aortic regurgitation of trivial to moderate degree was common, being detected in 28 (54%) by Doppler ultrasound and in 6 (12%) clinically. In a subgroup of 22 patients who were studied preoperatively and again early postoperatively (mean 6 weeks), new aortic regurgitation was found in 8 (36%) and was graded as trivial in all. Aortic regurgitation is a common complication related to ventriculomyectomy and ventriculomyotomy in patients with hypertrophic obstructive cardiomyopathy. Although initially trivial, the regurgitation may progress in severity over time. The regurgitation has been well tolerated in all patients studied to date.

Aortic Valve↗
PubMed1989

A simplified concept for a bileaflet atrioventricular valve that maintains annular-papillary muscle continuity.

We have developed a simplified concept for a bileaflet atrioventricular prosthesis that can be constructed from a simple sheet of glutaraldehyde preserved pericardium. The valve has no rigid ring or stent and no cloth sewing ring. Insertion of the valve reestablishes normal continuity between the annulus and the papillary muscles. We have replaced the mitral valve in nine dogs using this prosthesis. All valves have been competent with excellent valve opening areas as confirmed by echo-Doppler assessment. Studies up to 4 1/2 months have confirmed excellent hemodynamics and there has been no evidence of early tissue failure. Possible advantages of this simple valve design are improved hemodynamics, ease of construction and insertion, and low cost.

Animals↗
PubMed1989

Survival and bioprosthetic valve failure. Ten-year follow-up.

Between 1976 and 1982, 413 consecutive patients underwent valvular replacement with a bioprosthesis. Aortic valve replacement was performed in 240 patients, mitral valve replacement in 132, and multiple-valve replacement in 41. Four prostheses were employed: Carpentier-Edwards porcine (n = 336), Angel-Shiley porcine (n = 23), Hancock porcine (n = 11), and Ionescu-Shiley pericardial (n = 43). Follow-up was conducted between 5 and 12 years postoperatively and was 98% complete. Survival was 65 +/- 4% at 10 years and was independently influenced by advancing age, poor ventricular function, male sex, concomitant coronary artery bypass surgery, and valvular type. The risk of structural valvular dysfunction, reoperation, and any valve-related mortality and morbidity was significantly increased with the Ionescu-Shiley pericardial prosthesis. Long-term survival after valvular replacement was influenced by patient- and valve-related factors. The Ionescu-Shiley pericardial valve had an unusually high incidence of premature failure.

Adult↗
PubMed1988

Hypertrophic cardiomyopathy.

Hypertrophic cardiomyopathy is a diverse clinical and pathophysiologic disorder of unknown cause that principally involves the left ventricle and is manifested as asymmetric or concentric hypertrophy. If asymmetric, the hypertrophy is usually greatest in the ventricular septum, but variations occur in which the hypertrophy may be maximal at the mid-ventricular level, at the apex, or rarely, in the free wall of the left ventricle. Right ventricular involvement is usually less evident. The principal abnormality in systole is the obstruction to left ventricular outflow caused by systolic anterior motion (SAM) of the anterior or posterior mitral leaflet(s) with mitral leaflet-septal contact. SAM occurs as the result of the Venturi forces created by the rapid ejection of blood through an outflow tract that is narrowed by upper septal hypertrophy, drawing the mitral leaflet(s) anteriorly. The time of onset and duration of mitral leaflet-septal contact determine the magnitude of the pressure gradient. Mitral regurgitation invariably accompanies the obstruction to outflow. Ventriculomyectomy surgery, by thinning the septum and widening the outflow tract, abolishes the abnormal mitral leaflet motion and, consequently, the obstruction to outflow and the mitral regurgitation. In symptomatic patients with resting obstruction this form of surgery more dramatically relieves the systolic abnormalities and the accompanying symptoms than any form of medical therapy currently available. The extent of hypertrophy is believed to be the principal determinant of impaired left ventricular relaxation and increased chamber stiffness that characterize diastole in hypertrophic cardiomyopathy. Diastolic dysfunction is common to most such patients irrespective of the presence or absence of outflow obstruction. Calcium entry blockers may improve the left ventricular relaxation process and relieve symptoms in patients with hypertrophic cardiomyopathy, particularly the subgroup with no obstruction to outflow. Atrial and ventricular arrhythmias are responsible for a significant proportion of the morbidity and mortality, and their prevalence appears to depend on the presence of obstruction and the extent of hypertrophy. Thus, the major manifestations of hypertrophic cardiomyopathy in systole and diastole, as well as the disturbances in rhythm, appear to be related to the site and/or extent of the hypertrophic process. We have learned much about hypertrophic cardiomyopathy in the 30 years since its modern description. The vast majority of symptomatic patients can now be improved with specific medical or surgical therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Arrhythmias, Cardiac↗
PubMed1987

Evidence for true obstruction to left ventricular outflow in obstructive hypertrophic cardiomyopathy (muscular or hypertrophic subaortic stenosis).

In obstructive hypertrophic cardiomyopathy (muscular or hypertrophic subaortic stenosis), there is rapid early systolic ejection through an outflow tract that is narrowed by ventricular septal hypertrophy. This results in Venturi forces acting on the mitral leaflets, which cause mitral leaflet systolic anterior motion. Subsequent mitral leaflet-septal contact results in obstruction to left ventricular outflow and concomitant mitral regurgitation. Evidence is provided that the subaortic pressure gradient in obstructive hypertrophic cardiomyopathy reflects true obstruction to left ventricular outflow. It is important to distinguish this truly obstructive subaortic pressure gradient, due to mitral leaflet-septal contact, from an early systolic impulse gradient, as well as from the intraventricular pressure difference that may be encountered in midventricular obstruction or cavity obliteration.

Aortic Valve Stenosis↗
PubMed1987

Aortic valve replacement with a small prosthesis.

A small aortic prosthesis can be inserted in selected patients with excellent symptomatic improvement. A prospective evaluation was performed on 321 consecutive patients undergoing isolated aortic valve replacement between January 1982 and December 1984. Smaller prostheses (19 or 21 mm, predominantly pericardial valves, 132 patients) were inserted in older patients (p = .0001), women (p = .0001), smaller patients (body surface area: p = .0001), and patients with aortic stenosis (p = .0001). Twelve patients died in-hospital (3.7%) and 33 died during the follow-up period, producing an actuarial survival of 80% +/- 4% at 48 months. Survival was independently predicted by advancing age (p = .009), the preoperative NYHA functional class (p = .04) but not valve size (p = .28). Eighty-nine percent of patients were NYHA class I or II postoperatively compared with 22% preoperatively. Symptomatic recovery was similar for those with smaller size valves. Postoperative Doppler echocardiography in 57 patients revealed significant differences in aortic valve areas and gradients between the valve sizes. The 19 mm pericardial valves had the smallest areas (1.0 +/- 0.3 cm2) and the highest gradients (34 +/- 20 mm Hg). The aortic valve gradient was significantly related to cardiac output and valve size (p = .0001 by analysis of covariance). Linear regression analyses were used to estimate the aortic valve gradient during exercise (a 50% increase in cardiac output). The estimated exercise gradient was disturbingly high for the 19 mm valves (55 +/- 16 mm Hg), but the estimated exercise gradients for the 21, 23, and 25 mm valves were similar, all below 30 mm Hg. Aortic valve replacement with a small prosthesis resulted in excellent symptomatic improvement and acceptable resting valve gradients. However, a 19 mm prosthesis may produce prohibitive gradients during exercise, which may limit symptomatic recovery and should be avoided in active patients.

Actuarial Analysis↗
PubMed1987

Results of surgery for hypertrophic obstructive cardiomyopathy.

Between 1971 and March 1986, 61 patients underwent surgery for hypertrophic obstructive cardiomyopathy. Age at operation varied from 3.5 to 76 years (mean 38). The standard approach was a generous transaortic myectomy. One-quarter of the patients underwent concomitant repair of associated lesions. There was one operative and two late deaths, for an actuarial 5 years survival 93% (+/- 8%). Average follow-up is 3 years per patient. Sixty-four percent of these patients are asymptomatic and another 30% were in New York Heart Association class II. Persistent symptoms were usually related to arrhythmias. Early atrioventricular block did not occur, but two patients were paced for complex arrhythmias 3 and 4 years after surgery. Hemodynamic studies (n = 22), two-dimensional echocardiographic (n = 47), and Doppler assessments (n = 23) demonstrated a left ventricular outflow tract pressure gradient of 70 and 14 mm Hg before and after surgery, respectively, left ventricular diastolic pressure of 18 and 14 mm Hg, percent of patients with mitral regurgitation of 70% and 30%, percent of patients with systolic anterior motion of 100% and 35%, and percent of patients with aortic insufficiency of 9% and 49%. Eight-six percent of the patients catheterized had no resting obstruction. Subaortic myectomy produces symptomatic improvement by reducing the left ventricular outflow tract pressure gradient, mitral regurgitation, and left ventricular end-diastolic pressure, and probably improves longevity.

Adolescent↗