Search PubMed⌕ Search

Biomedical subjects

T M Bashore

Publications and source records attributed to T M Bashore.

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

Complications related to percutaneous transvenous mitral commissurotomy.

Recent randomized studies have demonstrated that percutaneous transvenous mitral commissurotomy (PTMC) has similar efficacy compared to surgical commissurotomy. Compared with surgery, PTMC is associated with shorter hospital stays, reduced patient discomfort, and significantly lower costs. The challenge of PTMC remains to provide increased safety. The most serious risks of balloon commissurotomy include cardiac perforation and embolic stroke. The creation of severe mitral regurgitation also limits the effectiveness of the procedure and occasionally leads to the requirement for emergency mitral valve replacement. Since 1986, procedure-related mortality has ranged from 0-2.7% with lower mortality rates reported recently. The most frequent cause of procedure-related death has been left ventricular (LV) perforation. This is almost exclusively a complication associated with the double balloon technique, which requires LV guidewires. Cardiac perforation due to inadvertent atrial perforation during transseptal catheterization may occur with the Inoue technique as well, but this tends to be less severe and has not resulted in death. Embolic stroke has occurred in 1.1-5.4% of cases. The incidence of embolic events has been favorably influenced by routine preprocedure transesophageal echocardiography (TEE), eliminating patients with left atrial thrombi. Significant mitral regurgitation occurs in 3.3-10.5% of patients undergoing balloon mitral commissurotomy. Fortunately, mitral regurgitation infrequently requires emergency surgery (0.3-3.3% of cases). Iatrogenic atrial septal defects are usually of no clinical consequence. Their frequency has been reduced with the use of the Inoue balloon catheter system and they rarely require surgical repair.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization↗
PubMed1994

Adult patients with congenital heart disease.

Adult patients with congenital heart disease present complex problems that require individualized management. Unfortunately, few physicians who care for adults with congenital heart disease have received adequate specific training to deal with their problems. Pediatric cardiologists who are familiar with congenital heart disease often refer patients to adult cardiologists after adolescence. And adult cardiologists have not traditionally had much training or experience in dealing with congenital heart disease. The cardiac needs of these patients are often best managed through the collaborative efforts of adult and pediatric cardiologists, cardiac surgeons, specialized nurse clinicians, and social workers. Of course, it is crucial to their optimal care that there be involvement of a primary care physician who can help with their many medical, surgical, and psychosocial problems.

Adult↗
PubMed1993

Usefulness of dobutamine echocardiography for detecting restenosis after percutaneous transluminal coronary angioplasty.

To determine the usefulness of dobutamine stress echocardiography for detecting restenosis after percutaneous transluminal coronary angioplasty, the results of coronary arteriography and dobutamine stress echocardiography were compared in 103 patients 6 months after percutaneous transluminal coronary angiography. The dobutamine stress echocardiograms were obtained on the same day as the coronary arteriograms, which were analyzed by both quantitative and visual estimates of luminal narrowing. The angiographic restenosis rate was 44% by quantitative and 31% by visual estimates of stenosis. Dobutamine stress echocardiography was abnormal in 38% of previously dilated regions with restenosis and normal in 79% of previously dilated regions without restenosis by quantitative coronary angiography. Dobutamine stress echocardiography was concordant in 69% of 16 patients with multivessel disease compared with 40% of 41 patients with 1-vessel disease (p < 0.05). By quantitative coronary angiography, 64% of patients with significant disease in the left anterior descending artery were identified by dobutamine stress echocardiography compared to 12 and 24% of patients with disease in the left circumflex and right coronary arteries, respectively (p < 0.009). Concordance was seen in 79% of patients with baseline wall motion abnormalities compared with 54% of patients without baseline wall motion abnormalities. Dobutamine stress echocardiography has a low sensitivity but high specificity for detecting restenosis after coronary angioplasty, which may be explained in part by the high prevalence of 1-vessel disease in this patient population. The variables associated with significantly higher degrees of concordance were the presence of left anterior descending artery disease, multivessel disease, and baseline wall motion abnormalities.

Adult↗
PubMed1993

In vivo validation of compensatory enlargement of atherosclerotic coronary arteries.

Necropsy examinations and epicardial ultrasound studies have suggested that atherosclerotic coronary arteries undergo compensatory enlargement. This increase in vessel size may be an important mechanism for maintaining myocardial blood flow. It also is of fundamental importance in the angiographic study of coronary disease progression and regression. The purpose of this study was to determine, using intracoronary ultrasound, whether coronary arteries undergo adaptive expansion in vivo. Forty-four consecutive patients were studied (30 men, 14 women; mean age 56 +/- 10 years). Eighty intravascular ultrasound images were analyzed (32 left main, 23 left anterior descending and 25 right coronary arteries). Internal elastic lamina area, a measure of overall vessel size increased as plaque area expanded (r = 0.57, p = 0.0001, SEE = 5.5 mm2). When the left main, left anterior descending and right coronary arteries were examined individually, there continued to be as great or greater positive correlation between internal elastic lamina and plaque area (left anterior descending: r = 0.75, p = 0.0001; right coronary arteries: r = 0.63, p = 0.0007; left main: r = 0.56, p = 0.0009), implying that each of the vessels and all in aggregate underwent adaptive enlargement. When only those vessels with < 30% area stenosis were examined, internal elastic lamina correlated well with plaque area (r = 0.79, and p = 0.0001), and for each 1 mm2 increase in plaque area, internal elastic lamina increased 2.7 mm2. This suggests that arterial enlargement may overcompensate for early atherosclerotic lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1993

Unrecognized left main coronary artery disease in patients undergoing interventional procedures.

Selective, coronary arteriographic, catheter-based, intravascular ultrasound images were obtained to determine the presence and extent of angiographically undetected or underestimated left main (LM) coronary arterial narrowing in patients receiving coronary interventional therapy. Coronary arteriograms were determined to be either normal or abnormal by visual inspection. Abnormal arteriograms were digitized and quantitated using a semiautomated edge-detection algorithm. Thirty-eight patients receiving percutaneous treatment of stenoses in the left coronary artery system were studied. Optimal LM coronary angiograms were obtained in 2 views, and intravascular ultrasound images were obtained after the coronary interventional procedure. Intravascular ultrasound detected plaque in 24 of 27 angiographically normal LM arteries (89%), whereas narrowing was observed in 11 of 11 angiographically abnormal LM arteries (100%). Eight of 38 patients (21%) had > 40% area stenosis by intravascular ultrasound. In patients with angiographic disease, there was no correlation between quantitative angiographic and ultrasound percent area stenosis (r = 0.12; p = 0.72; SEE 19%). The median plaque area was not different between angiographically normal (0.05 cm2; 0.03, 0.08 [25th, 75th percentile]) and abnormal (0.06 cm2; 0.03, 0.1) patients. The median percent area stenosis in arteriographically normal subjects (26%; 14, 32%) was less than that in abnormal ones (37%; 20, 46%) (p = 0.03). Unrecognized LM disease is widespread and often underestimated in patients with normal LM angiograms undergoing interventional procedures. Plaque area is similar for angiographically normal and insignificantly abnormal vessels. This study suggests that intravascular ultrasound overcomes the limitations of silhouette imaging and can be a clinically useful, adjunctive method to evaluate LM coronary artery disease.

Algorithms↗
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

Comparison of balloon valvuloplasty with operative treatment for mitral stenosis.

To determine the optimal role for percutaneous balloon mitral valvuloplasty or open mitral commissurotomy, the outcome of 164 consecutive patients undergoing either percutaneous balloon mitral valvuloplasty, open mitral commissurotomy, or mitral valve replacement for mitral stenosis was reviewed. No preoperative differences existed between percutaneous balloon mitral valvuloplasty and open mitral commissurotomy in age, symptoms, or mitral valve characteristics. Symptoms improved similarly in all groups, and median hospital stays after procedures were 2, 9, and 10 days for percutaneous balloon mitral valvuloplasty, open mitral commissurotomy, and mitral valve replacement (p < 0.005). Actuarial survivals at 36 months did not differ significantly (83% +/- 6%, 94% +/- 4%, and 90% +/- 4%). Actuarial freedoms from subsequent mitral valve procedures at 36 months were 66% +/- 7%, 87% +/- 6%, and 100% +/- 13% (p < 0.005), with the linearized rate of subsequent mitral valve procedures being 12% +/- 3%, 4% +/- 2%, and 1.2% +/- 0.8%/patient-year for percutaneous balloon mitral valvuloplasty, open mitral commissurotomy, and mitral valve replacement (p < 0.01). Prior mitral commissurotomy increased the likelihood of subsequent mitral procedures after percutaneous balloon mitral valvuloplasty from 10% +/- 3% to 20% +/- 7%/patient-year.

Adult↗
PubMed1993

Aortic/mitral obstruction and coarctation of the aorta.

The prevalence, anatomy and physiology, clinical manifestations, laboratory findings, and management of patients with aortic/mitral obstruction and coarctation of the aorta are assessed. Subaortic stenosis reviewed includes discreet membranous and tunnel subaortic stenosis as well as hypertrophic obstructive cardiomyopathy. The discussion of valvular aortic stenosis includes both congenital and acquired forms of the disease. Supravalvular aortic stenosis is described along with coarctation of the aorta. Mitral valvular stenosis includes the congenital as well as acquired variety with focus on the congenital lesion. Current opinion regarding the medical, the cardiac catheterization, interventional, and the surgical approaches to therapy is presented.

Aortic Coarctation↗
PubMed1992

Methodologic issues in clinical evaluation of stenosis severity in adults undergoing aortic or mitral balloon valvuloplasty. The NHLBI Balloon Valvuloplasty Registry.

Although both catheterization and Doppler measures of valvular stenosis severity have been validated, each has specific advantages and limitations, particularly in the setting of balloon valvuloplasty. Invasive valve area and mean pressure gradient recorded immediately before and after aortic (n = 589) or mitral (n = 608) catheter balloon valvuloplasty were compared with Doppler valve area and mean pressure gradient recorded less than 30 days before and 24 to 72 hours after the procedure. For aortic stenosis, Doppler valve area ranged from 0.1 to 1.4 cm2 before and 0.2 to 2.3 cm2 after catheter balloon valvuloplasty. Doppler and invasive aortic valve areas differed by less than or equal to 0.5 cm2 in 99% and by less than 0.2 cm2 in 92% of patients. Linear correlation was higher before versus after catheter balloon valvuloplasty, for both valve area (r = 0.49 vs r = 0.35, p = 0.01) and mean pressure gradient (r = 0.64 vs r = 0.50, p = 0.01). Group mean invasive valve area was slightly smaller before (0.50 vs 0.59 cm2, p less than 0.0001) but was not different after (0.80 vs 0.78 cm2, p = 0.16) catheter balloon valvuloplasty. Variables affecting the valve area differences were cardiac output, aortic regurgitation, heart rate and blood pressure. Mean pressure gradient differences were related to echo quality, blood pressure and mitral regurgitation. For mitral stenosis, 2-dimensional echocardiographic valve area ranged from 0.4 to 2.8 cm2 before and 0.7 to 3.8 cm2 after catheter balloon valvuloplasty. Two-dimensional echocardiography and invasive mitral valve areas differed by less than or equal to 0.5 cm2 in 96% and by less than 0.2 cm2 in 81% of cases. Linear correlation was not different before versus after catheter balloon valvuloplasty for two-dimensional echocardiographic valve area (r = 0.40 vs 0.36), pressure halftime valve area (r = 0.31 vs 0.32) or mean pressure gradient (r = 0.55 vs r = 0.46). Group mean 2-dimensional echocardiography and pressure halftime valve areas were larger than invasive valve areas before (1.09 vs 1.02 cm2, p = 0.001) and smaller after (1.71 vs 2.02 cm2, p less than 0.0001) catheter balloon valvuloplasty. Important variables affecting the differences were mitral regurgitation, interatrial shunt, cardiac output and heart rate. Nonsimultaneous studies, differing volume flow measurements, and the underlying accuracy of each technique largely account for discrepancies between these methods. The clinical use of each will depend on its ability to predict long-term patient outcome.

Adult↗
PubMed1992

Left ventricular filling and ventricular diastolic performance after percutaneous balloon mitral valvotomy.

The time course of left ventricular (LV) filling and LV diastolic performance were examined in 27 consecutive patients in sinus rhythm before and acutely after balloon mitral valvotomy (BMV). The mitral valve area acutely increased from 1.1 +/- 0.3 to 2.1 +/- 0.8 cm2. Simultaneous pressure-volume data were obtained using digital subtraction left ventriculography and LV micromanometer pressure before and 10 minutes after BMV. The time constant of LV isovolumic relaxation was unchanged after BMV (50 +/- 10 ms before BMV vs 47 +/- 13 ms after BMV). In addition, values before and after BMV for LV end-diastolic volume (123 +/- 29 vs 125 +/- 36 ml), end-diastolic pressure (11 +/- 4 vs 12 +/- 4 mm Hg) and diastolic filling time (337 +/- 126 vs 338 +/- 152 ms) were not altered by the procedure. After BMV the peak diastolic filling rate (403 +/- 143 vs 469 +/- 302 ml/s) was maintained despite a 36% reduction in left atrial filling pressure. There was a trend toward earlier occurrence of the peak filling rate (196 +/- 127 vs 146 +/- 148 ms, p = 0.08). The percentage of diastolic filling in the first third of diastole, however, was similar (42 +/- 9 vs 48 +/- 16%) before and after the procedure. Thus, the time course of LV filling is not significantly altered acutely after BMV, but is maintained at reduced left atrial filling pressure. Neither LV relaxation or LV chamber compliance are altered acutely after BMV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Quantitative and qualitative coronary angiographic analysis: review of methods, utility, and limitations.

Coronary angiography continues to be the pivotal study in the diagnosis and treatment of ischemic cardiac disease. Although angiographic equipment and imaging techniques have advanced over the past three decades, the analysis of coronary angiograms, by visual estimated percent diameter stenosis, has remained unchanged in most clinical catheterization laboratories. Rapid, computerized angiographic analysis systems are now available that remedy the inherent imprecision and inaccuracies plaguing visual coronary analysis. Despite its advantages, successful QCA is quite dependent on meticulous attention to radiographic and angiographic technique, even more so than with visual analysis. Although the available QCA systems can reproducibly and accurately define the site and degree of coronary stenosis, they cannot routinely determine whether an obstruction is flow limiting. Several methods, some based on extrapolations of quantitative measures alone, and others based on digital subtraction angiography, have been developed to determine the physiologic impact of a given coronary lesion. Recent observations have demonstrated, however, that even if the physiologic consequences of an obstruction are known, the prognosis of the lesion over time cannot be predicted. The qualitative, morphologic characteristics of a lesion are as, or more, important than the quantitative lesion attributes in determining an atheroma's behavior and stability, and hence, qualitative descriptors should be incorporated into QCA analyses. Although not currently available, future QCA systems will provide, by automated analysis, reproducible and accurate measures of absolute obstruction, physiologic data describing the flow limiting characteristics of a lesion, and qualitative, morphologic lesion descriptors. Implementation of these systems should provide more consistent and accurate prognostic and pathophysiologic information, thereby helping to refine and more effectively direct therapeutic interventions in coronary artery disease.

Algorithms↗
PubMed1992

Use of balloon occlusion to improve visualization of anomalous pulmonary venous return in an adult with cor triatriatum.

Cor triatriatum, although rare in adults, is often associated with anomalous pulmonary venous return. Accurate diagnosis of the pulmonary venous return and its anatomic connections is essential in planning proper surgical correction. This case illustrates the advantage of selective pulmonary artery angiography in obtaining accurate detail of the pulmonary venous anatomy from digital subtraction levophase images. Selective right and left pulmonary angiography was performed using a balloon catheter to simultaneously occlude the opposite pulmonary artery. This technique was well tolerated and greatly enhanced visualization of the anomalous pulmonary venous connections, allowing proper planning for corrective surgery.

Angiography, Digital Subtraction↗
PubMed1992

Factors influencing immediate results, complications, and short-term follow-up status after Inoue balloon mitral valvotomy: a North American multicenter study.

Clinical trials with the Inoue mitral valvotomy balloon have recently begun in the United States. We assessed the effects of 17 demographic, echocardiographic, procedural, and hemodynamic variables on the immediate results, complications, and short-term follow-up of 200 patients in 15 centers undergoing valvotomy with this device. The study population had a mean age +/- SD of 53 +/- 15 years, and the total echocardiographic score was 7.2 +/- 2.4. Valvotomy was technically successful in 96.5% of procedures and increased the mean mitral valve area from 1.0 +/- 0.3 to 1.8 +/- 0.7 cm2 (p less than 0.001); 72% had an increase in valve area greater than or equal to 50%, and 67% had a final area greater than or equal to 1.5 cm2. Major procedural complications included cardiac tamponade during transseptal puncture (1.0%), systemic embolism (1.5%), and severe mitral regurgitation (2.4%); there were no procedural deaths and one hospital death. Multivariate analysis identified the absence of prior surgical commissurotomy and younger age as significant predictors of the gain in mitral valve area, but the correlation coefficients were low. Although the absence of subvalvular disease on echocardiograms was a predictor of a final valve area greater than or equal to 1.5 cm2, the total echocardiographic score did not correlate well with the immediate outcome (r = 0.01, p = NS). No variable was identified as predictive of restenosis, which occurred according to echocardiographic criteria in 14 of 66 (21%) patients evaluated 6 months after valvotomy. Good hemodynamic results with valvotomy were achieved in the majority of patients with low complication rates by many investigators with the use of the Inoue balloon device.(ABSTRACT TRUNCATED AT 250 WORDS)

Balloon Occlusion↗
PubMed1992

Congenital aortic stenosis and patent ductus arteriosus in the adult.

Concurrent aortic stenosis and patent ductus arteriosus are not infrequent in children but are rare in adults. An adult case is described with diagnosis by cardiac catheterization and magnetic resonance imaging and with management by combined aortic valve replacement and patent ductus ligation. Review of the English-language literature produced only 8 such cases in adults, 2 of which were managed by a single-stage operation. Successful diagnosis in the adult requires careful observation at cardiac catheterization, and simultaneous valve replacement and ductus ligation may be a useful option in patient management.

Aged↗