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Biomedical subjects

T Feldman

Publications and source records attributed to T Feldman.

At least 73 records · Page 4Linked to original sources
PubMed1994

Hemodynamic results, clinical outcome, and complications of Inoue balloon mitral valvotomy.

Percutaneous transvenous mitral commissurotomy (PTMC) was performed in 290 patients enrolled from 16 clinical centers in the United States and Canada. The mean age was 54 +/- 15 years and the mean total echocardiographic score was 7.3 +/- 2.8. Mitral valve dilatation resulted in an increase in mitral valve area from 1.0 +/- 0.3 to 1.7 +/- 0.6 cm2 (P < 0.001). Technical success, defined as final mitral area > or = 1.5 cm2 or a > or = 50% increase in area, was achieved in 83% of patients. Significant complications included mitral valve replacement in the hospital 1.0% and hospital death in 1.4%. Failure to cross the mitral valve occurred in 1.7%. Other complications that did not interfere with discharge from the hospital with a completed PTMC procedure occurred in 12.1% of patients. Among patients with successful PTMC, the valve area remained constant over a 24-month follow-up period. Although a minority of patients were NYHA Class I or II prior to PTMC, > 80% remained in Class I or II throughout the 2-yr follow-up period. The overall results in this registry demonstrate that the acute hemodynamic results of the procedure are excellent, the incidence of procedure related complications is acceptable, and a majority of patients remain symptomatically improved during a 2-yr follow-up period.

Adolescent↗
PubMed1994

Technique of percutaneous transvenous mitral commissurotomy using the Inoue balloon catheter.

Percutaneous transvenous mitral commissurotomy (PTMC) with the Inoue balloon has had increasing use internationally since its introduction in 1984. This device was designed specifically for mitral commissurotomy and differs substantially from conventional large diameter peripheral arterial or valvuloplasty balloon catheters. It is constructed of two layers of latex with a nylon mesh in between. The latex is extremely compliant, whereas the nylon mesh limits the maximum inflated diameter of the balloon and also gives it a unique shape and set of inflation characteristics. The balloon inflates in three stages. The front half inflates first, creating the appearance of a balloon flotation catheter. The proximal half of the balloon inflates next, creating an hourglass shape. When straddling across the valve, this allows self-positioning of the balloon. Finally, the center portion inflates, resulting in commissurotomy. The technique of commissurotomy involves introducing the balloon into the left atrium over a guidewire and then passing it into the left ventricle with the distal portion of the balloon inflated in a manner analogous to crossing the tricuspid valve with a pulmonary artery flotation catheter. Thus a guidewire is not used to enter the left ventricle with this technique. Increasing inflation volumes allow a single balloon catheter to be inflated to a variety of sizes, allowing stepwise dilatation of the mitral valve in a manner analogous to coronary angioplasty. This report describes the performance of this technique in detail, with practical approaches to many common problems encountered during PTMC.

Angioplasty, Balloon↗
PubMed1993

Percutaneous mitral balloon valvotomy and the new demographics of mitral stenosis.

OBJECTIVE: This review discusses the latest developments in selected clinical features and catheter-based therapy of mitral stenosis. DATA SOURCES: English-language journal articles and reviews in the clinical and epidemiological literature as related to mitral valve stenosis from 1965 through March 1993, identified by bibliography review and expert consultation. STUDY SELECTION: Selected studies included clinical trials with adequate patient population description and short- and long-term (5 years) follow-up for topics related to mitral valve stenosis in the clinical literature. DATA EXTRACTION: Two reviewers participated in extracting the data with the aim of presenting a balanced and comprehensive review of the subject. DATA SYNTHESIS AND CONCLUSIONS: The main conclusions are (1) mitral stenosis should no longer be viewed as a largely "geriatric disease" in the United States due to a recent inflow many young immigrants from countries where rheumatic fever continues partially or wholly unabated; (2) clinical and anatomical features of mitral stenosis are age-dependent; when clinical presentation occurs at 30 vs 70 years of age, for example, the degree of valve obstruction may be similar but differences exist in the frequency of atrial fibrillation, the magnitude of reduction in cardiac output, the degree of valve deformity and calcification, and the frequency of coexistent coronary artery disease; and (3) mitral stenosis therapy has undergone a reorientation with the introduction of percutaneous mitral balloon valvotomy, which has proven to be safe, cost-effective, and to provide short- and long-term improvements in symptomatic and hemodynamic status in selected patients.

Catheterization↗
PubMed1993

Comparison of results of percutaneous balloon valvuloplasty in patients with mild and moderate mitral stenosis to those with severe mitral stenosis. The North American Inoue Balloon Investigators.

Most reported studies of percutaneous balloon valvuloplasty in adults with acquired mitral stenosis have used patients with severely stenosed valves. The risks and benefits of valvuloplasty were examined in a multicenter registry of patients to determine whether balloon valvuloplasty can effectively dilate less severely obstructed valves, and to clarify the role of this procedure in symptomatic patients with mild and moderate mitral stenosis. The study groups were derived from the North American Inoue Balloon Valvuloplasty Registry. Full hemodynamic data were available in 264 patients; 45 (17%) with mild or moderate mitral stenosis (mitral valve area > or = 1.3 cm2) were compared with the remaining 219 with severe mitral stenosis (valve area < 1.3 cm2). Percutaneous balloon valvuloplasty was performed using the anterograde transseptal technique with an Inoue balloon. The mean age of patients with mild and moderate mitral stenosis was 53 +/- 13 years, and all were symptomatic with a mean New York Heart Association functional class of 2.9 +/- 0.7. Balloon valvuloplasty resulted in an increase in calculated mitral valve area from 1.4 +/- 0.1 to 2.3 +/- 0.7 cm2 (p < 0.05), and a final valve area > or = 1.9 cm2 was achieved in 37 patients (82%). There were no procedural deaths, but complications included right atrial perforation, transient ischemic attack and emergency surgery for severe mitral regurgitation. One-year follow-up evaluation revealed symptomatic improvement in most patients (mean New York Heart Association class 1.4 +/- 0.6; p < 0.0001). However, 2 patients needed repeat valvuloplasty for restenosis, and 5 had mitral valve replacements.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Rheumatic mitral stenosis. On the rise again.

Rheumatic mitral stenosis remains an important cause of exertional dyspnea, pulmonary congestion, atrial fibrillation, and stroke. Detection rests on careful auscultatory examination and detailed review of chest films. Diagnosis is confirmed by echocardiographic examination; cardiac catheterization is important in symptomatic patients to evaluate the severity of stenosis and associated lesions. Treatment of pulmonary congestion and control of heart rate in patients with atrial fibrillation remain major medical goals. Percutaneous balloon commissurotomy is preferred for most patients with predominant mitral stenosis and for those with contraindications to valve replacement. Implantation of a prosthetic valve is best for patients with significant mitral regurgitation, multivalve disease, associated coronary artery disease that requires bypass, or mitral valve deformity too severe to allow adequate balloon commissurotomy.

Atrial Fibrillation↗
PubMed1993

Percutaneous transvenous mitral commissurotomy using the Inoue balloon catheter.

Since its inception in 1982, percutaneous transvenous mitral commissurotomy (PTMC) with the Inoue balloon catheter has gained increasingly wide use internationally. The procedure is technically successful in over 90% of patients, and the long-term durability of commissurotomy is excellent in those with pliable mitral valve leaflets and minimally deformed submitral apparatus. PTMC offers an alternative to patients previously not considered candidates for surgery, where no alternative had existed in the past. After transseptal puncture, PTMC using the Inoue balloon can be accomplished easily in the majority of patients. In comparison to double balloon mitral valvotomy, the postdilatation valve area is similar, the incidence of mitral regurgitation is not different, and the fluoroscopic and procedure time are markedly shorter. While patients with little valve deformity are excellent candidates for this procedure, and those not considered candidates for surgical therapy are also easily defined, selection of patients for balloon dilatation among those with significant valve deformity who are otherwise candidates for valve replacement therapy remains a challenging problem.

Catheterization↗
PubMed1993

Effect of balloon size and stepwise inflation technique on the acute results of Inoue mitral commissurotomy. Inoue Balloon Catheter Investigators.

Currently percutaneous transvenous mitral commissurotomy (PTMC) is performed by most operators using stepwise inflation of the Inoue balloon beginning at a small diameter and increasing size by a sequence of inflations to nominal diameter. The effect of balloon size on procedure results using the Inoue balloon has not been evaluated. In 260 patients final balloon inflation was to nominal size in 42% of pts, larger than nominal size (overinflated) in 10%, and less than nominal size (underinflated) in 48% of pts. The average number of inflations was 3 (range 1-9). Pressure gradient and Doppler mitral regurgitation (MR) were assessed after each inflation. When MR increased, further inflations were not done. Patients in whom the balloon was overinflated underwent more balloon inflations than those in whom it was inflated to nominal size (5.0 +/- 2.1 vs. 2.9 +/- 1.4, p < 0.01). Those with balloon underinflation had fewer balloon inflations (2.4 +/- 1.2 vs. 2.9 +/- 1.4, p < 0.01). The post PTMC valve area in patients with overinflation was slightly less than those with nominal inflations (1.6 +/- 0.4 vs. 1.8 +/- 0.7), and with underinflation the valve area was no different compared to nominal inflation. Using a stepwise procedure, if mitral regurgitation was noted to increase after a balloon inflation, the procedure would be stopped even if less than an ideal result was achieved. Fewer inflations were done in patients in whom the balloon was inflated to less than nominal size because of the appearance of mitral regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Calibration↗
PubMed1993

Restenosis following successful balloon valvuloplasty: bone formation in aortic valve leaflets.

Restenosis after balloon aortic valvuloplasty is common, occurring in as many as half or more of patients in the first year. To gain understanding of the mechanisms of restenosis we examined results of second dilatations and the histology of restenosed valves excised during valve replacement for restenosis. Eleven patients with calcific aortic stenosis underwent second valvuloplasty for restenosis. The mean age was 82 +/- 6 years. The interval between first and second dilatation was 14.7 +/- 8.5 months. First valvuloplasty resulted in an increase in valve area from 0.63 +/- 0.23 to 1.09 +/- 0.32 cm2 (p < 0.01). The valve area found after symptoms recurred was 0.56 +/- 0.18 cm2, not significantly different from the prevalvuloplasty dimensions. Second dilatation resulted in a mean aortic valve area of .76 +/- 0.22 cm2 (p = 0.011 vs results of first valvuloplasty). The change in valve area after first dilatation was 0.45 +/- 0.17 vs 0.20 +/- 0.13 cm2 after second dilatation (p < 0.01). Multiple histologic sections from excised, restenosed valves from five additional patients showed zones of active capillary and cellular proliferation and fibrosis in crevices between calcific nodules in three cases. Associated foci of ossification were seen in two of these. Stenotic nonvalvuloplasty control valves (n = 19) showed no ossifications. In conclusion, histologic changes in restenosed valves differ from those seen initially in calcific aortic stenosis, with granulation tissue, fibrosis, and ossification being present. These findings may help to explain the limited results of second dilatations for restenosis.

Aged↗
PubMed1993

Mechanisms and outcome of severe mitral regurgitation after Inoue balloon valvuloplasty. North American Inoue Balloon Investigators.

OBJECTIVES: The purpose of this study was to assess the incidence, mechanism and outcome of severe mitral regurgitation after treatment of mitral stenosis with percutaneous mitral valvuloplasty using the Inoue balloon. BACKGROUND: Severe mitral regurgitation occurs in up to 15% of percutaneous balloon valvuloplasty procedures for acquired mitral stenosis. The incidence and mechanism of production of mitral regurgitation with the recently introduced single-balloon Inoue technique have not been characterized. METHODS: We examined the incidence, mechanism, predictors and outcome of severe mitral regurgitation after Inoue balloon valvuloplasty in 280 patients in the North American multicenter registry. Twenty-one patients who developed either clinically significant or angiographically severe regurgitation were identified, and their echocardiograms were reviewed to determine the mechanism of regurgitation. These patients were then compared with the remaining patients without severe regurgitation to identify predictors of this outcome. RESULTS: The incidence of severe regurgitation in this study was 7.5%, and the mean grade of angiographic regurgitation in these patients increased from 0.9 +/- 1.0 to 2.8 +/- 0.7 (p < 0.05). The most common cause of regurgitation (43%) was rupture of chordae tendineae to the anterior or posterior mitral leaflet. Tearing of a leaflet (usually the posterior one) occurred in 30% of patients; and no recognizable structural abnormality, with wide splitting of the commissures and a central regurgitant jet, was present in five patients (26%). All patients with definite posterior leaflet tears had heavily calcified leaflets. Patients who developed severe regurgitation had fewer balloon inflations and a higher grade of preexisting mitral regurgitation but were otherwise similar to the remaining patients without severe regurgitation. During 6-month follow-up, 71% of the patients with severe regurgitation were treated surgically; the grade of regurgitation decreased in four patients (19%), and five patients (24%) have not required mitral valve replacement during 18 +/- 5 months of follow-up. CONCLUSIONS: Severe mitral regurgitation is a relatively infrequent complication of Inoue balloon valvuloplasty and results from disruption of the valve integrity, including chordal rupture and leaflet tearing. Careful balloon positioning may help avoid chordal rupture, and heavily calcified posterior leaflets may be at greater risk of tearing. Most patients who develop severe regurgitation will require nonemergency mitral valve replacement.

Adult↗
PubMed1993

Today's approach to PTCA: how it is performed, who might benefit. When can angioplasty replace medical therapy or bypass surgery?

The use of percutaneous transluminal coronary angioplasty has expanded tremendously over the past decade. Because equipment has improved and physicians' experience has increased, the procedure is often appropriate for patients with complex lesions or difficult coronary anatomies. Currently, stenoses are successfully opened in more than 90% of patients. Angioplasty is an alternative to medical therapy for patients with one- or two-vessel disease; in some patients with multivessel disease, it is an alternative to coronary artery bypass graft surgery. Among elderly patients, those who are poor candidates for bypass surgery, those who have had previous bypass surgery, and those with acute myocardial infarction or cardiogenic shock, coronary angioplasty may be particularly useful.

Angioplasty, Balloon, Coronary↗
PubMed1993

Update on PTCA: what are its limitations? Can they be overcome by new devices? A look at atherectomy, intra-arterial stents, and laser catheters.

Complications limiting the use of percutaneous transluminal coronary angioplasty (PTCA) include abrupt vessel closure and restenosis. Certain coronary lesions, such as chronic total occlusions and diffuse or long stenoses, pose serious technical difficulties. New devices may overcome some of these limitations. For example, atherectomy may prove useful for thrombotic vessels or diffusely diseased vein grafts, and it may lower restenosis rates in larger vessels. Stents are currently used as a bailout measure when acute dissection occurs. Although lasers produce smoother margins than does conventional PTCA and effectively ablate atherosclerotic plaque material, the restenosis rate associated with use of these devices may be similar to that of conventional PTCA.

Angioplasty↗
PubMed1993

Turbulence intensity in aortic stenosis: frequency characteristics and effects of alterations in left ventricular function.

Turbulent blood flow can occur downstream from a stenosis. The purpose of this study was to quantitate turbulence intensity and its frequency characteristics in the ascending aorta in adult patients with and without valvular stenosis, and to use extrasystoles to analyze the effects of changes in left ventricular function on turbulence. Turbulence intensity was determined from the digitized, high frequency oscillations seen in high fidelity pressure recordings of 25 patients with valvular aortic stenosis. The intensity of turbulence was quantitated as the root-mean-square (mmHg) of pressure fluctuations and as the total spectral power (mmHg2/beat) of the frequency spectrum between 25 Hz and 400 Hz. Frequency characteristics were summarized by the mean and median frequency of spectral power and partitioning the spectrum into 25 Hz segments. Ten adult patients without aortic valve or outflow tract abnormalities served as controls. Adult patients with aortic stenosis had significantly more turbulence in the ascending aorta than controls (total spectral power 1577 +/- 450 mmHg2 vs. 198 +/- 22 mmHg2, p < 0.01). Furthermore, the frequency distribution in aortic stenosis was biased towards higher frequencies (mean frequency 35 +/- 14 Hz vs 54 +/- 2 Hz, p < 0.001). Turbulence intensity in aortic stenosis demonstrated beat to beat modulation by left ventricular function. The total spectral power of a sinus beat was 1888 +/- 762 mmHg2, and fell to 137 +/- 63 mmHg2 in a weak premature beat, and rose to 3618 +/- 1178 mmHg2 in a potentiated post- extrasystolic beat (p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

ST segment alternans during coronary angioplasty.

Four patients with severe proximal or mid-LAD stenosis were noted to have ST alternans during balloon angioplasty. Neither mechanical alternans nor increased ventricular ectopy were noted. In contrast to prior descriptions in animals or patients with variant angina, ST alternans did not occur following a premature ventricular contraction. Frequent use of calcium channel blockers during PTCA may interfere with the mechanism leading to electrical alternans and its consequences as seen in animal studies, accounting for the low frequency with which this phenomenon is noted during PTCA.

Adult↗
PubMed1992

Plasma lipoprotein (a) protein concentration and coronary artery disease in black patients compared with white patients.

PURPOSE: This study examines the relation between lipoprotein (a) protein levels and other lipid parameters and coronary artery disease in white and black patients. PATIENTS AND METHODS: Plasma lipoprotein (a) protein levels were measured prior to coronary angiography in a population of 127 white and 111 black patients. Each angiogram was given a total coronary artery disease score based on the number and severity of atherosclerotic coronary lesions. RESULTS: White and black patients exhibited no differences in total plasma cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. Black patients had higher lipoprotein (a) protein levels than white patients (8.6 versus 4.0 mg/dL; p < 0.0001). The extent and severity of coronary artery disease was the same in white and black patients. White and black patients with coronary artery disease had higher lipoprotein (a) levels than patients without coronary lesions (4.37 versus 1.99 mg/dL, p = 0.027 for white; 9.23 versus 6.87 mg/dL, p = 0.072 for black). In both groups of patients, there was a weak but significant positive correlation between lipoprotein (a) protein levels and coronary artery disease score. CONCLUSION: Lipoprotein (a) is higher in patients with coronary artery disease. Black patients have higher plasma lipoprotein (a) protein levels than white patients and a comparable degree of coronary artery disease. It follows that the cardiovascular pathogenicity of lipoprotein (a) is not significantly greater in black patients despite higher lipoprotein (a) levels.

Black or African American↗
PubMed1992

Effect of valve deformity on results and mitral regurgitation after Inoue balloon commissurotomy.

BACKGROUND: The effect of valve deformity and patient age adversely affect the results of percutaneous transvenous mitral commissurotomy (PTMC) with conventional balloons. METHODS AND RESULTS: These factors were characterized after PTMC with the Inoue balloon. The increases in mitral valve area and mitral regurgitation after the procedure were evaluated comparing echocardiographic score of 8 or less versus more than 8, age of less than 60 versus age of 60 years or more, and age of less than 70 versus age of 70 years or more. One hundred sixty-two patients (mean age, 52 +/- 14 years) were studied. For the entire group, mitral valve area increased from 1.0 to 1.8 cm2 (p less than 0.001). Valve area increased from 1.0 +/- 0.3 to 1.8 +/- 0.6 cm2 in patients with echocardiographic score of 8 or less (n = 102) and from 1.0 +/- 0.3 to 1.7 +/- 0.5 cm2 with echocardiographic score of more than 8 (n = 44). Patients less than 60 years old (n = 104) had increases in valve area from 1.0 +/- 0.3 to 1.8 +/- 0.6 cm2 versus 1.0 +/- 0.4 to 1.8 +/- 0.6 cm2 for those 60 years old or older (n = 50) (p = NS). There was no significant difference in resultant valve area when the age division was increased to less than 70 versus 70 years or more. Similarly, the percentage of patients with 2+ or greater increase in mitral regurgitation was not different for those with higher than for those with lower echocardiographic scores (4% versus 12%, p = NS), age of less than 60 versus age of 60 years or more (10% versus 10%, p = NS), or age of less than 70 versus age of 70 or more years (9% versus 18%, p = NS). Valve replacement for mitral regurgitation was performed in four patients (one emergency), all with echocardiographic scores of less than 8. CONCLUSIONS: Age and extent of valve deformity do not have significant effects on acute results of PTMC using the Inoue balloon. Unique balloon geometry or the controlled, stepwise balloon sizing may explain these acceptable acute results in patients with more-deformed valves.

Adult↗