PubMed HealthSearch

Biomedical subjects

P C Block

Publications and source records attributed to P C Block.

At least 19 recordsLinked to original sources

Late (two-year) follow-up after percutaneous balloon mitral valvotomy.

Percutaneous balloon mitral valvotomy (PBMV) compares well with surgical commissurotomy, showing comparable improvement in symptoms and catheterization-proven valve area early after the procedure. This study reports the New York Heart Association class, mitral valve area calculated by echocardiography, and the results of transseptal cardiac catheterization 2 years after PBMV. The data are compared with the status immediately before and after PBMV. Forty-one patients returned to enter the study (mean follow-up time 24 +/- 3 months). All patients were evaluated clinically by the same investigator who had seen them at the time of PBMV. Transseptal cardiac catheterization and echocardiographic analysis (2-dimensional and Doppler echocardiography) were performed on the same day. At follow-up, 17 patients were class I, 20 were class II, and 4 were class III. Although the mitral valve area calculated by cardiac catheterization increased significantly from immediately before to immediately after PBMV there was a decrease in the calculated mitral valve area at 2-year follow-up. Echocardiographic analysis did not show as large an increase in mitral area, immediately after PBMV, and no significant decrease in mitral valve area at 2 years (before PBMV planimetry 1.1 +/- 0.1 cm2; immediately after 1.8 +/- 0.1 [p less than 0.05]; follow-up 1.6 +/- 0.1 [p = not significant compared with immediately after PBMV]). Doppler halftime measurements were similar. PBMV is effective therapy with good midterm results for selected patients with mitral stenosis.

Adult

Unusual sequelae after percutaneous mitral valvuloplasty: a Doppler echocardiographic study.

Percutaneous mitral valvuloplasty is a promising new technique for the treatment of mitral stenosis, with a relatively low complication rate reported to date. To assess the sequelae of this procedure, Doppler echocardiographic studies were prospectively performed before and after percutaneous mitral valvuloplasty in a series of 172 patients (mean age 53 +/- 17 years). After balloon dilation, mitral valve area increased from 0.9 +/- 0.3 to 2 +/- 0.8 cm2 (p less than 0.0001), mean gradient decreased from 16 +/- 6 to 6 +/- 3 mm Hg (p less than 0.0001) and mean left atrial pressure decreased from 24 +/- 7 to 14 +/- 6 mm Hg (p less than 0.0001). Although most patients were symptomatically improved, six (4%) were identified who had unusual sequelae evident on Doppler echocardiographic examination immediately after percutaneous mitral valvuloplasty. These included rupture of a posterior mitral valve leaflet, producing a flail distal leaflet portion with severe mitral regurgitation detected on Doppler color flow mapping (n = 1); asymptomatic rupture of the chordae tendineae attached to the anterior mitral valve leaflet with systolic anterior motion of the ruptured chordae into the left ventricular outflow tract (n = 1); a double-orifice mitral valve (n = 1); and evidence of a tear in the anterior mitral valve leaflet (n = 3), producing on both pulsed Doppler ultrasound and color flow mapping a second discrete jet of mitral regurgitation in addition to regurgitation through the main mitral valve orifice. All six patients made a satisfactory recovery and none has required mitral valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Immediate and long-term outcome of percutaneous mitral valvotomy in patients 65 years and older.

BACKGROUND: We analyzed the immediate and long-term outcome of percutaneous balloon mitral valvotomy (PMV) in 99 patients who were greater than or equal to 65 years of age (81 women and 18 men; mean +/- SEM age, 72 +/- 0.5 years). METHODS AND RESULTS: There were 84 patients in New York Heart Association (NYHA) class III or IV; 26 patients had previous surgical commissurotomy; 64 had one or more comorbidities; 73 had fluoroscopically visible mitral valve (MV) calcification; and 63 had echocardiographic score greater than 8 (mean +/- SEM score, 9.2 +/- 0.2). There were three procedural deaths, all occurring in our early experience. Pericardial tamponade occurred in five patients, thromboembolism in three, and transient atrioventricular block in one. After PMV, MV area was greater than or equal to 1 cm2 in 86 patients and greater than or equal to 1.5 cm2 in 56. A successful outcome (defined as MV area greater than or equal to 1.5 cm2 without a greater than or equal to 2-grade increase in mitral regurgitation and without left-to-right shunt with a pulmonary-to-systemic flow ratio of greater than or equal to 1.5:1) was achieved in 46 patients. The best multivariate predictor of success was the combination of echocardiographic score, NYHA functional class, and inverse of MV area. Mean follow-up was 16 +/- 1 months. Actuarial survival (79 +/- 7% versus 62 +/- 10%, p = 0.04), survival without MV replacement (71 +/- 8% versus 41 +/- 8%, p = 0.002), and survival without MV replacement and NYHA class III or IV (54 +/- 12% versus 38 +/- 8%, p = 0.01) at 3 years were significantly better in the successful group of 46 patients than in the unsuccessful group of 53 patients. Low echocardiographic score was the only independent predictor of survival. Lack of MV calcification and low NYHA class, low mean left atrial pressure, and low pulmonary artery pressure were the independent predictors of event-free survival. CONCLUSIONS: PMV can be performed safely in selected patients greater than or equal to 65 years old with good immediate and long-term results. In addition to clinical examination, echocardiographic evaluation of the mitral valve and fluoroscopic screening for valvular calcification are the most important steps in patient selection for successful outcome.

Actuarial Analysis

Atrial septal occlusion improves the accuracy of mitral valve area determination following percutaneous mitral balloon valvotomy.

We investigated the impact of the atrial communication on the mitral valve area calculation after percutaneous mitral balloon valvotomy in 17 patients (15 women, 2 men; mean age 56 +/- 4 years). The hemodynamic measurements and mitral valve area calculations were performed with and without balloon occlusion of the atrial septal puncture site. The mitral valve area determined with balloon occlusion was significantly smaller than the mitral valve area determined without occlusion (1.6 +/- 0.1 vs. 1.9 +/- 0.1 cm2, P less than 0.01), and was similar to the echocardiographically determined valve area (1.6 +/- 0.1 cm2). This decrease in the calculated mitral valve area with occlusion was associated with a decrease in the measured cardiac output, without a change in the mitral valve gradient or the diastolic filling period. Occlusion of the atrial septal puncture site may permit more accurate determination of the mitral valve area and thus provide a better reference point for future comparison should the question or restenosis arise.

Cardiac Catheterization

Percutaneous balloon pericardial window for patients with malignant pericardial effusion and tamponade.

We performed percutaneous balloon pericardial window (PBPW) in 8 patients (age 40 to 70 yrs; 4 men, 4 women) with malignant pericardial effusion and tamponade. Pericardial window was indicated because they continued to drain greater than 100 ml/day of pericardial fluid through the pigtail catheter for greater than or equal to 3 days. A 0.038 inch guidewire was advanced through the pigtail catheter into the pericardial space and then the catheter was removed. A 20 mm diameter, 3 cm long balloon dilating catheter was advanced to straddle the parietal pericardium. Manual inflations were performed until the waist produced by the pericardium disappeared. All patients tolerated the procedure well with minimal discomfort and with no complications. A left or bilateral pleural effusion occurred in all patients after PBPW. No patient developed recurrent pericardial tamponade at a mean follow-up of 6 +/- 2 months. Thus, PBPW is a useful and safe technique to avoid surgery in patients with malignant pericardial effusion and tamponade.

Balloon Occlusion

Comparison of early versus late experience with percutaneous mitral balloon valvuloplasty.

The immediate outcome of the first 150 patients (Group 1) and the last 161 patients (Group 2) who underwent percutaneous mitral balloon valvuloplasty was compared. There was no difference between the two groups in age, gender, New York Heart Association functional class, presence of calcification, atrial fibrillation, degree of mitral regurgitation, mean pulmonary artery pressure, left atrial pressure, cardiac output, pulmonary vascular resistance, mitral valve gradient and mitral valve area. Fewer patients in Group 1 than Group 2 had an echocardiographic score less than or equal to 8 (62% versus 69%, respectively, p = 0.02). The atrial septum was dilated with an 8 mm balloon in 74% of patients in Group 1 and with a 5 mm balloon in all patients in Group 2. Ratio of effective balloon dilating area to body surface area was larger in Group 1 than in Group 2 (4.05 +/- 0.07 versus 3.7 +/- 0.03 cm2/m2, p = 0.0001). A good result (mitral valve area greater than or equal to 1.5 cm2) was obtained in 77% and 75% in Groups 1 and 2, respectively (p = NS). After percutaneous mitral valvuloplasty, a greater than or equal to 2 grade increase in mitral regurgitation was noted in 12% of Group 1 and 6% of Group 2 (p = 0.02) and a left to right shunt was detected in 22% of Group 1 and 11% of Group 2 (p = 0.0001). There were three procedure-related deaths in Group 1, but none in Group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Catheterization

Percutaneous mitral balloon valvotomy.

Percutaneous balloon mitral valvotomy is a technique that allows relief of mitral stenosis without thoracotomy. Commissurotomy of the mitral valve with proper sized balloons that are placed antegrade by means of a transseptal catheterization results in good immediate and midterm results in most patients. Younger patients with echocardiographic scores of 8 or lower and who are without atrial fibrillation, mitral regurgitation or valvular calcification, and histories of surgical commissurotomy are the best candidates for PMV. Nevertheless, many patients who are not ideal candidates for PMV also derive substantial relief from this procedure. Mortality and morbidity related to the procedure are low in most experienced centers. Complications include pericardial tamponade, thromboembolism, rhythm abnormalities, left to right shunting, and mitral regurgitation. The survival with freedom from mitral valve replacement at 2 years after PMV is 84%. In addition to history and physical examination, echocardiography has a central role in the selection of patients for PMV.

Adult

Predictors of increased mitral regurgitation after percutaneous mitral balloon valvotomy.

Left ventriculography (LVG) was performed to assess severity of mitral regurgitation (MR) on a scale of 0-4+ in 157 patients before and immediately after percutaneous mitral balloon valvotomy (PMV). There were 129 women and 28 men aged 51 +/- 1 (range 13-87) yr. With PMV, mitral valve area increased from 0.9 +/- 0.1 cm2 to 2.0 +/- 0.1 cm2 (P less than .0001). Increase in mitral regurgitation (MR) occurred in 69 patients (44%). Patients were divided into two groups based on increase in MR after PMV. Group A (n = 136) had 0-1+ increase in MR. Group B (n = 20) had greater than or equal to 2+ increase in MR after PMV. The only predictor of increase in MR greater than or equal to 2+ was the ratio of effective balloon dilating area to body surface area (EBDA/BSA). EBDA/BSA was 4.0 +/- 0.1 cm2/m2 in Group A vs. 4.37 +/- 0.2 cm2/m2 in Group B (P = .02). Follow-up of patients in Group B showed: Four patients remained NYHA Class III and required mitral valve replacement 4.3 +/- 1.1 (range 5-21) mo after PMV. One patient who had undergone combined aortic and mitral valvotomy died in the hospital of worsening heart failure. One patient died 1 mo later of sepsis related to a dental abscess. Follow-up of the remaining 14 patients at 9.5 +/- 1.1 (range 2-7) mo showed 10 in NYHA Class I and four in NYHA Class II. Eight of 15 patients (53%) who had repeat left ventriculogram at 9.0 +/- 0.8 mo after PMV had a decrease in MR of one grade when compared to LVG immediately after PMV.

Adolescent

Acquired Lutembacher syndrome or mitral stenosis and acquired atrial septal defect after transseptal mitral valvuloplasty.

Critical mitral stenosis in selected patients may be treated successfully with percutaneous mitral valvuloplasty. Complications of this procedure, particularly an atrial septal defect following transseptal approach, are generally of minor clinical significance. We describe a woman who initially underwent a successful percutaneous double-balloon mitral valvuloplasty via the transseptal approach. Three months later she presented with right-sided heart failure. Color Doppler echocardiography and cardiac catheterization demonstrated an atrial septal defect (ASD) as well as restenosis of the mitral valve. We conclude that significant ASDs may occur following transseptal mitral valvuloplasty with appearance of right ventricular failure and that color Doppler imaging aids in the diagnosis of this new variant of the classical Lutembacher syndrome.

Aged

Atrial septal defect after percutaneous mitral balloon valvuloplasty: immediate results and follow-up.

Percutaneous mitral balloon valvuloplasty was performed in 150 patients. There were 124 women and 26 men (mean age 53 +/- 1 years). A left to right shunt through the created atrial communication was present in 28 patients (19%) after valvuloplasty. The pulmonary to systemic flow ratio was greater than or equal to 2:1 in 4 patients and less than 2:1 in 24. Univariate predictors of left to right shunting after valvuloplasty included older age (p less than 0.01), lower cardiac output before mitral valvuloplasty (p less than 0.01), higher New York Heart Association functional class before valvuloplasty (p less than 0.05), presence of mitral valve calcification under fluoroscopy (p less than 0.01) and higher echocardiographic score (p less than 0.05). Multiple stepwise logistic regression analysis identified the presence of mitral valve calcification (p less than 0.02) and lower cardiac output (p less than 0.02) as the independent predictors of a left to right shunt through the atrial communication after balloon valvuloplasty. Follow-up (10 +/- 1 months) of patients with an atrial septal defect after valvuloplasty showed that 1) 6 patients died (3 in the hospital and 3 at 2, 16 and 18 months, respectively, after valvuloplasty); 2) an atrial septal defect was demonstrated in 3 of 6 patients who underwent mitral valve replacement (6 +/- 0.8 months after valvuloplasty); and 3) 13 patients were in functional class I, 2 patients were in class II and 1 patient was in class III at 13 +/- 1 months after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Prediction of successful outcome in 130 patients undergoing percutaneous balloon mitral valvotomy.

We studied 130 patients undergoing percutaneous balloon mitral valvotomy. The relation between valvular morphology according to a previously described echocardiographic scoring system and hemodynamic outcome expressed as qualitative ("good" and suboptimal) and as absolute change in valve area was analyzed. The relative importance of the individual components of this echocardiographic score (valvular thickening, mobility, calcification, and subvalvular disease) to the change in valve area after valvotomy was also examined. Mean transmitral pressure gradient decreased from 16 +/- 6 to 6 +/- 3 mm Hg (p less than 0.0001), and mitral valve area increased from 0.9 +/- 0.3 to 1.8 +/- 0.7 cm2 (p less than 0.0001). Results in individual patients were variable. Eighty-four percent (61 of 73) of patients with an echocardiographic score of 8 or less had a "good" outcome (final valve area greater than or equal to 1.5 cm2 and an increase in valve area of greater than or equal to 25%), whereas 58% (33 of 57) of patients with an echocardiographic score of 8 or more had a suboptimal result (p less than 0.001). The sensitivity of an echocardiographic score of 8 or less for predicting a "good" outcome was 72%, and the specificity was 73%. The echocardiographic score correlated negatively (r = -0.40, p less than 0.0001) with the absolute increase in mitral valve area after valvotomy, but there was substantial scatter in the data. Of the four components of the total echocardiographic score, valvular thickening correlated best with the absolute change in value area (r = -0.47, p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Restenosis after percutaneous transluminal coronary angioplasty--anatomic and pathophysiological mechanisms. Strategies for prevention.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA) probably results from pathophysiological mechanisms that are initiated during PTCA. Platelet deposition or exposed subendothelial connective tissue initiates complex blood element and vessel wall interactions that are not completely understood and leads to a proliferative response at the site of injury. The incidence of restenosis is also related to clinical, anatomic, and procedural variables. An increased frequency of restenosis is seen in patients who have recent onset of angina, unstable angina, or vasospastic angina, and in those who have diabetes. Stenoses in the proximal left anterior descending coronary artery, the ostium of the right coronary artery, and the proximal portion of a bypass vein graft have higher rates of restenosis than lesions at other sites. Restenosis can be predicted by an incomplete PTCA, which is identified by a high residual pressure gradient across the stenosis. Mechanical and pharmacological methods of preventing restenosis are under investigation. Intravascular stenting with expandable metal sleeves and laser angioplasty have shown encouraging results. Longer balloon inflation time can help prevent early elastic recoil. Platelet inhibitors (e.g., aspirin, dipyridamole, and sulfinpyrazone) do not appear to have an effect on restenosis. Agents, however, that interfere with platelet deposition at the PTCA site and that modify the effect of platelet-derived growth factor and medial cell proliferation show promise for control of restenosis.

Angioplasty, Balloon, Coronary

Echophonocardiography in patients undergoing percutaneous mitral balloon valvotomy (PMV): the learning curve of PMV.

Percutaneous mitral balloon valvotomy (PMV) was performed in 10 female patients with mitral stenosis; their mean age was 31 +/- 1 years. All patients underwent echophonocardiography (Echophono) before and less than 24 hours after PMV1. Cardiac catheterization and Echophono were repeated 10 and 22 months after PMV1. Eight patients with suboptimal results (defined as a post-PMV mitral valve area [MVA]/less than 1.0 cm2 and mean gradient greater than/10 mm Hg) underwent repeat PMV (PMV2) 10 months after PMV1. The Echophono data are correlated with clinical and hemodynamic changes produced by PMV1 and PMV2. MVA increased from 0.6 +/- 0.1 to 1.1 +/- 0.01 cm2 (p = 0.0009) when PMV1 was performed with a mean effective balloon dilating area (EBDA) of 5 +/- 0.19 cm2. MVA increased from 1.0 +/- 0.1 to 1.7 +/- 0.2 cm2 (p = 0.0002) when PMV2 was performed with larger EBDA (6.4 +/- 0.34 cm2). Two factors related to the learning curve account for the superior result of PMV2: (1) use of larger EBDA and (2) optimal position of the balloons parallel to the long axis of the left ventricle. PMV1 resulted in Echophono changes consistent with decreased severity of mitral stenosis: shortening of Q-S1 from 93 +/- 4 to 82 +/- 4 msec (p less than 0.05) and (Q-S1)-(S2-OS) from 1.8 +/- 0.8 to -0.9 +/- 0.6 (p less than 0.01); prolongation of S2-OS from 75 +/- 5 to 91 +/- 5 msec (p less than 0.05) and increase of EF slope from 7 +/- 1 to 17 +/- 4 mm/sec (p less than 0.05). Compared with PMV1, post PMV2 Echophono showed a further decrease in the severity of mitral stenosis: Q-S1 decreased to 78 +/- 3 msec and (Q-S1)-(S2-OS) decreased to -0.5 +/- 0.3 msec. S2-OS increased to 86 +/- 5 msec and EF slope increased to 22 +/- 4 mm/sec. The hemodynamic and Echophono changes produced by PMV1 and PMV2 persisted at the corresponding follow-up studies. There was no evidence of restenosis. Thus Echophono is a simple, low cost method helpful in the evaluation and follow-up of patients undergoing PMV.

Adolescent

Comparison of coronary artery bypass grafting and percutaneous transluminal coronary angioplasty as initial treatment strategies.

Early and late results of primary nonemergency coronary artery bypass grafting in 1,000 consecutive patients and primary nonemergency percutaneous transluminal coronary angioplasty performed concurrently in 389 patients were retrospectively compared. The coronary bypass population was significantly older and more symptomatic and had more prior myocardial infarctions, more left main and multiple-vessel coronary artery disease, and poorer ventricular function. Hospital mortality rates for coronary bypass grafting and angioplasty were 0.4% and 0.5%, respectively, and infarction rates were 1.7% and 5.1%, respectively (p less than 0.01). Including hospital events for the coronary bypass and angioplasty populations, actuarial survival at 5 years was 92.3% versus 96.3% (p = 0.04), freedom from myocardial infarction was 94.6% versus 88.1% (p less than 0.001), freedom from subsequent angioplasty was 99.5% versus 75.2% (p less than 0.001), freedom from subsequent coronary bypass grafting was 98.8% versus 84.9% (p less than 0.001), and freedom from all morbidity and mortality was 87.1% versus 66.0% (p less than 0.001), respectively. By Cox regression analysis for all 1,389 patients, only diminished ejection fraction and advanced age predicted poor long-term survival (p less than 0.001). The only significant predictor of nonfatal late events was having had coronary angioplasty.

Angioplasty, Balloon

Percutaneous aortic balloon valvuloplasty: its role in the management of patients with aortic stenosis requiring major noncardiac surgery.

Seven patients with severe aortic stenosis underwent percutaneous aortic balloon valvuloplasty in preparation for major noncardiac surgery. There were four men and three women (mean age 82 +/- 1.3 years, range 78 to 88). A significant reduction in the transaortic pressure gradient from 77 +/- 7.8 to 31 +/- 6.2 mm Hg (p = 0.002) and increase in calculated aortic valve area from 0.5 +/- 0.1 to 1.0 +/- 0.3 cm2 (p = 0.05) was noted. Three of the seven procedures were performed anterograde with use of transseptal puncture: two of the three because of abdominal aortic aneurysm and one because of peripheral vascular disease. All seven patients underwent uncomplicated noncardiac surgery under general anesthesia 10 +/- 4.3 days (range 0 to 29) after aortic valvuloplasty. One patient had exploratory laparotomy, one underwent stabilization of a hip fracture and two underwent resection of an abdominal aortic aneurysm. Of the three other patients who underwent colectomy, one had repeat aortic valvuloplasty and repair of a hip fracture 7 months later and one required exploratory laparotomy without repeat valvuloplasty 7 weeks later. Percutaneous aortic balloon valvuloplasty is an effective and safe procedure that may reduce the risk of general anesthesia and major noncardiac surgery in elderly patients with aortic stenosis.

Aged

Follow-up of patients undergoing percutaneous mitral balloon valvotomy. Analysis of factors determining restenosis.

This study reports the clinical follow-up (13 +/- 1 months) of 100 consecutive patients who underwent percutaneous mitral balloon valvotomy (PMV). Echocardiographic (n = 32) and cardiac catheterization (n = 37) data from this group are also included. Patients were divided into two groups by an echocardiographic score. PMV resulted in a good hemodynamic result (post-PMV mitral valve area, greater than or equal to 1.5 cm2) in 88% of patients with a score of 8 or less and 44% of patients with a score of more than 8. Eighty-eight percent of patients with a score of 8 or less (n = 57) were New York Heart Association (NYHA) functional Classes III and IV before PMV; at follow-up, 81% were NYHA Class I and 12% were NYHA Class II. There were no deaths; three patients underwent mitral valve replacement (MVR). Ninety-eight percent of patients with a score of more than 8 (n = 43) were NYHA Classes III and IV before PMV; at follow-up, 58% were NYHA Classes I and II. Seven patients who did not improve and were not surgical candidates died 3.8 +/- 1.2 months after PMV. Nine patients who were surgical candidates underwent elective MVR at 4 +/- 0.9 months after PMV. Repeat cardiac catheterization demonstrated restenosis in only one of 27 patients (4%) with a score of 8 or less. Mitral valve area after PMV was 1.9 +/- 0.1 cm2 and at follow-up was 2 +/- 0.1 cm2 (NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Fibrillation