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Biomedical subjects

R F Lewin

Publications and source records attributed to R F Lewin.

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

Percutaneous transluminal coronary angioplasty in patients over the age of 70 years.

Percutaneous transluminal coronary angioplasty was successfully performed in 207 of 242 patients over the age of 70 years. Multivessel disease was present in 71 per cent of patients; 93.0 per cent of patients had good left ventricular ejection fractions (greater than or equal to 35 per cent). Angioplasty was successful in 348 of 385 lesions dilated (90 per cent), with the desired degree of revascularization achieved in 90 per cent of patients with the dilatation of one or two lesions. The complications encountered included five Q wave infarctions (2.1 per cent), seven angioplasty-related deaths (2.9 per cent), and three emergency bypass surgeries (1.2 per cent). The cumulative probability of survival was 92 +/- 3 per cent at 63 months, and at a mean of 2.9 years 66 per cent of patients were angina-free. These data indicate that selected symptomatic coronary disease patients over the age of 70 years unsatisfactorily managed with medication have been successfully managed with coronary angioplasty. The results of coronary angioplasty compare favorably to those of coronary artery bypass surgery.

Aged↗
PubMed1989

Percutaneous transluminal coronary angioplasty in patients with severe left ventricular dysfunction.

Although bypass surgery can be utilized in the patient with impaired left ventricular function, the acute outcome (regarding morbidity and mortality) and long-term survival have significant associated problems. Percutaneous transluminal coronary angioplasty (PTCA) was implemented effectively as an accessory or alternative to coronary bypass surgery to treat obliterative coronary lesions in patients with severe ventricular dysfunction. The authors present data which indicate that PTCA should be considered in patients with left ventricular dysfunction as a primary therapeutic modality.

Aged↗
PubMed1989

Complex angioplasty: single versus multiple dilatations in multivessel coronary disease patients.

Percutaneous transluminal coronary angioplasty (PTCA) has become an accepted therapy in the management of selected patients with obstructive coronary disease, including selected patients with multivessel disease. This article reports the authors' experience with PTCA in patients who underwent single or multiple dilatation angioplasty, their outcome, and follow-up. It also provides an additional perspective to the multivessel coronary disease patient.

Adult↗
PubMed1989

Coronary angioplasty in patients with prior coronary artery bypass surgery: all prior coronary artery bypass surgery patients and patients more than 5 years after coronary bypass surgery.

Percutaneous transluminal coronary angioplasty (PTCA) has been used successfully in patients who have had prior bypass surgery (CABG) as a means of revascularizing the myocardium and avoiding repeat myocardial revascularization. However, angioplasty has been considered inappropriate as a means of dilating old saphenous vein grafts. The first section of this article details the authors' experience with PTCA of prior CABG patients, and the second section discusses the results of PTCA in the subset of patients 5 or more years after their last coronary bypass surgery. These data may make individuals rethink the appropriateness of PTCA in old saphenous vein grafts.

Aged↗
PubMed1988

Percutaneous transluminal coronary angioplasty in patients with two or more previous coronary artery bypass grafting operations.

Between 1979 and 1986, 65 of 76 patients (86%) (82% men, with a mean age of 58 +/- 8 years) with greater than or equal to 2 previous coronary artery bypass grafting (CABG) operations and symptomatic myocardial ischemia underwent successful percutaneous transluminal coronary angioplasty (PTCA). Sixty-two patients had 2 prior CABG operations, 10 had 3 and 4 had 4. Clinical characteristics included prior myocardial infarctions in 49 (65%), severe angina (class III or IV) in 47 (62%) and left ventricular ejection fraction less than or equal to 35% in 13 (17%). There were 139 lesions dilated: 1 lesion in 39 (51%), 2 in 22 (29%) and greater than or equal to 3 in 15 (20%) patients. Arterial lesions were successfully dilated in 71 of 81 cases (88%), vein grafts in 44 of 53 (83%) and mammary artery grafts in 3 of 5 (60%). In 12 patients, PTCA was used to dilate significant lesions less than 15 days after CABG in vessels which were unable to be bypassed. Significant complications were encountered in 4 patients (5%). These included 3 of 53 vein graft dilatations with embolization (6%), with 1 resulting in infarction and death, and 1 patient dying after emergency CABG. At hospital discharge, 65 patients were clinically improved. An apparent symptom-related lesion recurrence occurred in 23 of 65 patients (35%), with 5 patients dying of cardiac causes, 4 having CABG without previous angiography and 12 of 14 patients undergoing repeat successful PTCA (mean time and standard deviation 9 +/- 6 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1988

Effects of isosorbide dinitrates intravenously in high doses over a short period in anterior acute myocardial infarction.

The effects of intravenous isosorbide dinitrate administered in high doses over a short period of time in 17 patients (14 men, 3 women, mean age 67 years) with anterior wall acute myocardial infarction were evaluated. Patients were classified into 2 groups based on the electrocardiographic pattern of acute ischemia. Patients presented with anterior acute myocardial infarction; an electrocardiographic pattern of third-degree ischemia demonstrated a more favorable electrocardiographic and radionuclear angiographic evolution than similar patients who presented with an electrocardiographic pattern of second-degree ischemia.

Adult↗
PubMed1988

Percutaneous mitral valvuloplasty: retrograde, transarterial double-balloon technique utilizing the transseptal approach.

Between February 1985 and May 1987, 72 patients with mitral stenosis (MS) underwent percutaneous transluminal mitral valvuloplasty (PTMV). The retrograde transarterial double-balloon technique was used on 54/72 patients (75%); 16 males, 38 females; mean age: 39 +/- 11 years. Transseptal catheterization was used to place two 0.035", 350-cm exchange wires into the ascending aorta in order to be snared, retrieved, and exteriorized, each through a femoral artery. Over these wires, the balloon dilation catheters were advanced through the femoral artery, retrogradely, across the mitral valve, for PTMV. The transmitral mean gradient fell [18 +/- 4 to 9 +/- 5 mmHg (P less than 0.001)]; the cardiac output increased [5.1 +/- 0.8 6.1 +/- 0.8 L/min (P less than 0.001)]; the hemodynamically calculated valve area increased [1.2 +/- 0.2 to 2.3 +/- 0.6 cm2 (P less than 0.001)]; and the short axis two-dimensional echocardiographic valve area increased [1.1 +/- 0.3 to 2.2 +/- 0.7 (P less than 0.001)]. PTMV was unsuccessful in two patients (4%), due to the inability to maintain the inflated balloons in the mitral position. Significant complications were encountered in two patients: two strokes (3.7%) and one mortality from the stroke (1.4%). Significant mitral regurgitation occurred in two patients (3.7%); no post-PTMV hemodynamically significant atrial septal defects were detected. Follow-up (mean time: 11 +/- 6 months) of 43 patients showed a persistent improvement in echocardiographic findings in 27 (63%) and hemodynamically measured mitral valve area in the 16 patients in which cardiac catheterization was repeated. The retrograde, transarterial double-balloon technique can successfully accomplish PTMV with good results and an acceptable low morbidity and mortality.

Adult↗
PubMed1988

Probe, a balloon wire: initial experience.

Coronary angioplasty is unsuccessful in less than 3-5% of cases because the balloon catheter fails to follow a guidewire that has traversed a lesion. Between June 1986 and August 1987, 31 lesions were unable to be crossed with at least two standard angioplasty catheters. Finally, a 2.0-mm-diameter Hartzler LPS (ACS) was utilized and successfully crossed and dilated 16 out of 31 lesions (52%). In the remaining 15 lesions, the Probe (USCI) 2.0 mm diameter x 1.5 cm long balloon wire was able to cross the lesions in 13 (82%) and successfully dilated 12. In one case, lesion rigidity prevented the balloon from expanding at 14 atm. A right coronary artery lesion was attempted in 11 cases, and a left anterior descending and circumflex artery lesion in two patients each. No complications were encountered. In seven out of 12 successful Probe cases, a larger balloon catheter was used to further dilate the artery. This new balloon wire has increased our success rate in severe stenoses and in tortuous vessels with severe distal lesions, in which presently available angioplasty equipment has failed.

Angioplasty, Balloon↗
PubMed1988

Percutaneous transluminal coronary angioplasty in multivessel coronary disease patients: short- and long-term follow-up in single and multiple dilatations.

Transluminal coronary angioplasty was successfully performed in 658 of 752 patients with multivessel disease. An angiographic success was achieved in 1198 of 1358 lesions (88%). One lesion was attempted in 338 patients (45%); 2 in 273 (37%); 3, in 101 (13%); and, 4 or more in 40 cases (5.3%). Significant complications occurred in 39 patients (5.2%): 19 (2.5%) had a transmural infarction; 26 (3.5%) required urgent myocardial revascularization; and 14 (1.9%) died. An apparent lesion recurrence occurred in 233 of 658 (35%) patients with 162 of 171 (95%) having a successful second coronary angioplasty. A second apparent lesion recurrence occurred in 37 of 162 patients (23%) with 24 of 28 (86%) having a successful third coronary angioplasty. Clinical improvement (mean follow-up: 31 +/- 17 months) persisted in 81% of successful patients. The cumulative probability of survival was 91.5% at 72 months. Survival was adversely affected, at 63 months, by the presence of prior bypass surgery (no prior bypass surgery, 94% vs. prior bypass surgery, 86%; p less than 0.05): at 24 months by a low left ventricular ejection fraction (less than or equal to 35%, 82% vs. left ventricular ejection fraction greater than 35%, 95%; p less than 0.01) and, at 57 months, in the multiple dilatation group with prior bypass surgery (no bypass surgery 96% vs. prior bypass surgery 84%; p less than 0.05). Multiple dilatation had a beneficial effect upon survival, at 27 months, in patients with a left ventricular ejection fraction less than or equal to 35% [single dilatation, 74% vs. multiple dilatation, 93%; p less than 0.001], and in patients greater than or equal to 70 years, at 39 months (79% vs. multiple dilatation, 92%; p less than 0.01). These data suggest that coronary angioplasty can be an effective treatment in patients with multivessel coronary disease without the need to dilate all diseased vessels, with good success, acceptable complication rates, and a reasonable expectation of satisfactory long-term clinical improvement.

Actuarial Analysis↗
PubMed1988

Ventricular fibrillation in a patient with 'silent' mitral valve prolapse.

A patient with clinically silent mitral valve prolapse experienced an episode of out-of-hospital cardiac arrest due to ventricular fibrillation. This arrhythmia was easily replicated in the electrophysiology laboratory and despite treatment with amiodarone alone and amiodarone in combination with propranolol. Amiodarone in combination with quinidine prevented the induction of ventricular fibrillation and proved effective during a 3-year follow-up period. Even though a clear-cut relationship between the arrhythmias and mitral valve prolapse cannot be established, this case suggests that sudden death can occur in patients with mitral valve prolapse but without the known risk factors for the development of sudden death.

Adult↗
PubMed1988

Significance of the magnitude of a QS wave deflection in evaluating the uninvolved muscle in anterior wall myocardial infarction.

The significance of dynamic changes of the QS wave magnitude, as demonstrated in the precordial leads, within the natural evolution of acute anterior wall myocardial infarction (AAMI) was assessed in 25 patients within two weeks of their admission to the intensive cardiac care unit. Two sets of tests, including 12-lead electrocardiogram and a full radionuclear study, were performed in two time periods: (1) within the first 48 hours of admission; and (2) between the 12th and 15th day after admission. Comparison and correlation between the electrocardiographic data, QS waves in leads V2 and V3 and in V1 to V6 (sigma QV2-3 and sigma QV1-6), and radionuclear regional ejection fractions of the noninfarcted posterior muscle (inferior, infero-apical, and posterolateral regions and posterior index) were done. Significant linear correlations were demonstrated between the electrocardiographic variant differences in percentages (sigma QV2-3 and sigma QV1-6) and the radionuclear variant differences, especially the posterolateral and the infero-apical regions, as well as the posterior radionuclear index (r between 0.5 and 0.75; p less than 0.01). In addition, almost all of the patients who showed deepening of QS waves in the precordial leads also showed an increase in regional ejection fractions in uninvolved myocardium, and vice versa. It is concluded that the dynamic changes of the QS wave magnitude in the precordial leads within the evolution of acute anterior myocardial infarction well reflect the changes of the posterior noninfarcted muscle contraction and therefore offers a simple, inexpensive, and indirect electrocardiographic method for evaluating changes in contraction patterns of noninfarcted myocardium.

Electrocardiography↗
PubMed1987

Short- and long-term dobutamine treatment in chronic ischemic heart failure.

This study was undertaken in order to characterize the short-term (1 hour) and long-term (72 hours) effect of dobutamine on hemodynamic and regional ejection fraction parameters measured by radionuclear angiography in patients with chronic congestive heart failure due to coronary artery disease. Baseline hemodynamic and radionuclear parameters were measured and then intravenous dobutamine (8.5 mu/kg/min) was administered. The above parameters were determined again after 1 hour and 72 hours of continuous dobutamine administration. Sixty minutes (short-term) after dobutamine administration heart rate and cardiac index increased significantly (p less than 0.001 for both) and peripheral resistance decreased concomitantly (p less than 0.005). Global left ventricular ejection fraction (LVEF) as measured by multigated equilibrium nuclear angiography (MUGA) increased from 21.8 +/- 10.6% to 25 +/- 13.5 (p less than 0.02). Count-based mean regional ejection fraction in the septal, inferoapical, posterolateral (45 degrees left anterior oblique view) and inferior apical and anterolateral (30 degree right anterior oblique gated first pass) regions increased also. At 72 hours (long-term) after continuous dobutamine infusion, heart rate and cardiac index were still significantly higher and peripheral resistance lower than in the control study. However, global and count-based regional ejection fraction decreased to control values in the right anterior oblique view (first-pass analysis) and the left anterior oblique view (MUGA). Global LVEF measured in the right anterior oblique view by first-pass technique was significantly higher than control in the long-term study (23 +/- 9.7 vs. 27.8 +/- 2.4; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Coronary artery bypass surgery in patients over age 70 years: report from the Milwaukee Cardiovascular Data Registry.

Between 1972 and 1985, 674 coronary bypass patients greater than or equal to 70 years (70% male, mean age 73 years) were among 10,622 patients with both catheterization and operative data entered into the Milwaukee Cardiovascular Data Registry. These greater than or equal to 70 years patients were analyzed regarding the operative morbidity, the 30-day operative mortality and the operative mortality's relation to coronary artery disease and ventricular wall motion abnormalities. The operative mortality was not different for the 174 patients operated upon before and the 500 patients after 1980. A mean of 3.4 grafts were placed during surgery. The complications encountered included a 7.1% perioperative infarction rate, a 4.2% incidence of cerebrovascular accident, a 3.6% incidence of reoperation for bleeding, a 2.4% incidence of renal failure, and a 2.1% incidence of pulmonary embolism. The overall operative mortality was 7.4%. The extent of coronary artery disease was distributed among patients such that 8.4% had single-, 28.0% had double-, and 63.6% had triple-vessel disease. The operative mortality as related to the extent of coronary artery disease was 5.2% for single-, 8.9% for double-, and 7.0% for triple-vessel disease. The operative mortality was 6.7% with no and 7.9% with left ventricular wall motion abnormalities. The operative mortality was 1.9% with 1 segmental wall motion abnormality, and increased to 13.3% (p less than 0.05) with 4-6 segmental wall motion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗
PubMed1987

Natural course of electrocardiographic components and stages in the first twelve hours of acute myocardial infarction.

Time course evolution of R, Q, T and ST components of the electrocardiogram during the first 12 hours of an acute myocardial infarction was studied. A comparison between anterior-extensive and anteroseptal wall infarctions (anterior group), and inferior-extensive and inferior wall infarction (inferior group) showed appearance of significant Q waves within two hours in both groups. R wave loss was nearly a mirror image of Q wave development in both groups. T waves became negative and ST more isoelectric earlier in the inferior than in the anterior group. When combined variations of the four electrocardiographic components were analyzed, four stages of acute infarction were delineated. Stage I--tall R, no Q, ST elevation and positive T; Stage II--significant Q wave appearance; Stage III--negativity of T waves; and Stage IV--ST isoelectric. The inferior group reached stages III-IV within 12 hours; the anterior group remained mostly in stage II. An early appearance of Q waves correlated well with rapid progression to stages III-IV within 12 hours in both infarction groups.

Electrocardiography↗
PubMed1987

Multiple lesion transluminal coronary angioplasty in single and multivessel coronary artery disease: acute outcome and long-term effect.

Multiple lesion transluminal coronary angioplasty was performed in 428 patients. Angioplasty was attempted in 1,047 lesions (2.4/patient), with an angiographic success achieved in 94%: 2 lesions were attempted in 74%, 3 in 21%, 4 in 5% and 5 or more in 1% of cases. A clinical success was achieved in 404 (94%) of the patients: 95% with and 93% without prior surgery and in 94% of those with single vessel disease and 94% of those with multivessel disease. Significant complications occurred in 17 patients (4.0%): 11 (2.5%) had a transmural infarction, 9 (2.1%) required urgent surgery and 6 (1.4%) died. An apparent lesion recurrence occurred in 106 (26%) of 404 patients with 81 of 89 patients (91%) having a successful second angioplasty. A second apparent lesion recurrence occurred in 15 patients (19%), with 13 of the 15 patients having a successful third angioplasty. A sustained clinical improvement (mean follow-up period 28.3 +/- 16 months) was obtained in 208 (83%) of 250 patients with successful angioplasty. The cumulative probability of survival at 51 months was 93% in these 250 patients. Survival was adversely affected by the presence of prior bypass surgery (no prior surgery 97% versus prior surgery 81%; p less than 0.05). These data suggest that multiple lesion angioplasty can be successfully performed with a good success rate, an acceptable incidence of complications and a reasonable expectation of satisfactory long-term clinical improvement.

Angioplasty, Balloon↗
PubMed1987

Positivization of T wave with or without ST segment elevation in patients with unstable angina. Coronary angiographic findings and in-hospital prognosis.

The coronary angiographic findings and the in-hospital prognosis of unstable angina pectoris presenting with T wave positivization only (group A: 32 patients) or with additional ST segment elevation (group B: 27 patients) were evaluated. Clinical data and haemodynamic parameters before and during unstable anginal events showed no significant statistical difference, indicating blood flow reduction as the probable mechanism of ischaemia in both groups. The incidence of hospital myocardial infarction was higher in patients of group B (group A 6.24% vs group B 31%; P less than 0.02). Death due to haemodynamic deterioration occurred in 2 patients of group B. This finding can be partially explained by more developed collateral circulation in patients with T wave changes only (25 of 65 obstructed arteries in group A vs 8 out of 48 obstructed arteries in group B; P less than 0.05). Left ventricular function was comparable between the two groups. The extent, severity and location of coronary artery disease was similar in the groups. Thus, the electrocardiographic pattern of T wave changes only, in patients with unstable angina pectoris (group A) define a subgroup who have a favourable prognosis and development similar to patients with chronic stable angina pectoris. Urgent measures may be delayed in this group.

Adult↗