PubMed Health⌕ Search

Biomedical subjects

G W Vetrovec

Publications and source records attributed to G W Vetrovec.

At least 109 records · Page 6Linked to original sources
PubMed1988

Comparative dosing and efficacy of continuous-release nifedipine versus standard nifedipine for angina pectoris: clinical response, exercise performance, and plasma nifedipine levels.

To assess the dosing equivalency and the early and late antianginal efficacy of a gastrointestinal therapeutic system for once-daily, continuous-release nifedipine (N-GITS), 10 patients with stable angina pectoris, who were previously receiving chronic treatment with nifedipine, completed a 12-week trial comparing N-GITS with standard nifedipine. All patients (nine men and one woman; mean age 54 +/- 2 [SEM] years) who were receiving standard nifedipine (mean dose 40 +/- 5 mg/24 hr) for more than 2 weeks (mean 8 +/- 2 months, range 2 to 36 months) were switched to an equivalent once-daily dose (39 +/- 5 mg/24 hr) of N-GITS. Standard nifedipine and N-GITS were compared by symptom-limited exercise treadmill tests with a baseline test (A) performed 3 hours after a standard dose of nifedipine. Exercise tests were also performed after 2 weeks of treatment with N-GITS 3 hours (B) and 24 hours (C) after the drug was given, and after 12 weeks of treatment with N-GITS, 24 hours after dosing (D). Results of exercise tests showed no significant difference in mean exercise time--(A) 422 +/- 25 vs (B) 426 +/- 36 vs (C) 438 +/- 35 vs (D) 487 +/- 37 seconds. Likewise, there was no significant mean difference in peak double product, resting heart rate, peak exercise heart rate, or resting or maximal systolic blood pressure for any of the exercise test points. Furthermore, five patients (50%) reported side effects with standard nifedipine (all vasodilator-flushing, dizziness, or both), which resolved after treatment with N-GITS (p +/- 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1988

Triple vessel coronary angioplasty: acute outcome and long-term results.

Triple vessel coronary angioplasty, defined as angioplasty of one or more lesions in each of the three major coronary arteries (left anterior descending, left circumflex, right coronary artery) was performed in 50 (11%) of 469 patients who had angioplasty of multiple vessels. There were 32 men and 18 women with a mean age of 56 years. All 50 patients had severe three vessel coronary disease and represent approximately 5% of patients with three vessel disease who had revascularization in this institution; 8 (16%) had previous coronary bypass surgery, and 23 (46%) had previous myocardial infarction. Unstable angina was present in 33 patients (66%) and 96% had Canadian Heart Association class III or IV angina; mean left ventricular ejection fraction was 57 +/- 11%. Angioplasty was performed in 176 vessels (3.5 vessels per patient, range 3 to 6) and in 250 lesions (5 lesions per patient, range 3 to 9); angiographic success was achieved in 240 lesions (96%) and 166 vessels (94%). Success in all vessels attempted was achieved in 40 (80%) of the 50 patients. Clinical success (angiographic success associated with clinical improvement) was obtained in all 50 patients in whom triple vessel angioplasty was performed; none of them required urgent bypass surgery and 5 patients (10%) had a non-Q wave myocardial infarction. In four other patients triple vessel angioplasty was planned but not performed because of failure to dilate the primary vessel; urgent bypass surgery was required in one of these, who developed a Q wave infarction. Thus, overall clinical success in 54 patients was 93%; the incidence rate of myocardial infarction was 11%, and that of urgent surgery 1.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Hemodynamic dysfunction in obesity hypoventilation syndrome and the effects of treatment with surgically induced weight loss.

Obesity hypoventilation syndrome (OHS), defined as a PaO2 less than or equal to 55 mmHg and/or PaCo2 greater than or equal to 47 mmHg, was found in approximately 8% of morbidly obese patients undergoing gastric surgery for morbid obesity and was frequently associated with clinically significant pulmonary hypertension and cardiac dysfunction. Forty-six morbidly obese patients, 26 with and 20 without OHS, underwent preoperative pulmonary artery catheterization. Although the two groups had similar values for percent ideal body weight, blood pressure, and cardiac index, the OHS patients had significantly higher mean pulmonary artery pressures (PAP), p less than 0.0001, and pulmonary artery occlusion pressures (PAOP), p less than 0.01. Eighteen OHS patients were restudied 3-9 months after gastric surgery. PaO2 increased from 50 +/- 10 to 69 +/- 14 mmHg, p less than 0.0001, and PaCO2 decreased from 52 +/- 7 to 42 +/- 4 mmHg, p less than 0.0001), after the loss of 42 +/- 19% excess weight. These changes were associated with significant decreases in PAP (from 36 +/- 14 to 23 +/- 7 mmHg, p less than 0.0001) and PAOP (from 17 +/- 7 to 12 +/- 6 mmHg, p less than 0.01). Significant correlations were noted between PAP and PAOP (r = +0.8, p less than 0.0001) and PAP and PaO2 (r = -0.6, p less than 0.0001). Both left ventricular dysfunction, defined as a PAOP greater than or equal to 18 mmHg, as well as pulmonary artery vasoconstriction, defined as PAEDP greater than 5 mmHg above PAOP, contributed to pulmonary hypertension in OHS patients. In conclusion, weight loss after gastric surgery for morbid obesity significantly improved arterial blood gases and hemodynamic function in OHS patients.

Adult↗
PubMed1988

Applications of percutaneous transluminal coronary angioplasty in cardiac transplantation. Preliminary results in five patients.

Atherosclerotic coronary artery disease is the major cause of late cardiac transplant failure secondary to silent ischemia and infarction. To increase the longevity of cardiac homografts, we performed percutaneous transluminal coronary angioplasty (PTCA) in five male patients (aged 45 +/- 7 years, mean +/- SEM); 17 lesions were dilated during eight procedures 83 +/- 11 months after cardiac transplant. PTCA was successful (greater than or equal to 20% change in vessel diameter) in 13 of 17 (76%) lesions (the degree of prePTCA stenosis was 84% +/- 3% vs. 40% +/- 4% postPTCA; p less than or equal to 0.01). Multiple PTCA procedures were performed for progressive coronary artery disease in two patients; in one patient, two procedures were 13 months apart, and, in the second patient, another three procedures were 2 and 6 months apart. Indications for PTCA included reversible thallium perfusion defects, segmental left ventricular wall-motion abnormalities, or both in the distribution of proximal coronary artery stenoses. No deterioration occurred in the four unsuccessful PTCA attempts (two patients with initial total occlusion, and two patients in whom the lesion could not be crossed with a guidewire). Noninvasive evidence of ischemia was improved immediately after PTCA in all cases. Three patients remain alive 5, 7, and 11 months, respectively, after PTCA without evidence of new ischemia. One patient died 39 months after his first PTCA, while another patient was retransplanted 8 months after the first PTCA. Thus, PTCA can be performed in cardiac transplant patients with proximal major vessel coronary artery disease and may prolong cardiac homograft function.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Nifedipine gastrointestinal therapeutic system in stable angina pectoris. Results of a multicenter open-label crossover comparison with standard nifedipine.

To compare the clinical efficacy and dose equivalency of standard nifedipine versus a new gastrointestinal therapeutic system (GITS) formulation of nifedipine, 98 patients with chronic stable angina pectoris participated in a 14-week, multicenter, open-label, crossover trial. All patients were administered nifedipine capsules for one month prior to study entry and continued receiving other antianginal, non-calcium blocker medications. Ninety-one patients (93 percent), 80 men and 11 women, mean age 62 +/- 1 years, completed the trial, which included two weeks receiving standard nifedipine followed by 12 weeks receiving nifedipine GITS starting at a dosage equal to the 24-hour total dose of nifedipine capsules and titrated upward as necessary. However, throughout the trial, mean nifedipine dosage was similar on nifedipine GITS compared with standard nifedipine. Angina frequency was significantly less with nifedipine GITS at Weeks 6, 10, and 14 (0.8 episodes/week) compared with baseline with standard nifedipine (1.3 episodes/week, p less than 0.05). Likewise, nitroglycerin consumption was also less at Weeks 6, 10, and 14, but only significantly less at Week 6 (nifedipine 1.2/week versus nifedipine GITS at six weeks, 0.7/week; p less than 0.05). Resting hemodynamic parameters, including systolic and diastolic blood pressure and heart rate, were not significantly different with standard nifedipine versus nifedipine GITS during the 12-week study. Total incidences of side effects were similar for both treatments (standard nifedipine, 16; nifedipine GITS, 17). However, incidence of vasodilator side effects (flushing, dizziness, and light-headedness) was significantly less frequent with nifedipine GITS (standard nifedipine, 12; nifedipine GITS, six; p less than 0.05). Thus, results from this open-label, crossover trial suggest that nifedipine GITS dosing is similar to multidose standard nifedipine with equivalent 24-hour efficacy for nifedipine GITS.

Aged↗
PubMed1987

Valvuloplasty.

Explore the source record for details and available documents.

Aortic Valve Stenosis↗
PubMed1986

Angiographic patterns of restenosis after angioplasty of multiple coronary arteries.

To assess angiographic patterns of restenosis after percutaneous transluminal coronary angioplasty (PTCA) of multiple coronary arteries, angiograms were reviewed in 40 patients with clinical recurrence after PTCA of multiple arteries. Clinical recurrence was defined as return of symptoms after successful PTCA of more than 1 major artery or branch and angiographic evidence of restenosis of 1 or more lesions. In these 40 patients, 83 arteries (2.1 arteries per patient) and 103 narrowings (2.6 narrowings per patient) were successfully dilated. Restenosis developed in 57 of 83 arteries at risk (69%): 23 patients (58%) had restenosis in only 1 artery and 17 (42%) in 2 arteries. Restenosis occurred in 63 of 103 lesions at risk (61%): 20 patients (50%) had restenosis of 1 narrowing, 17 (43%) had restenosis of 2 narrowings and 3 (7%) had recurrence of 3 narrowings. Only 13 patients (33%) had restenosis of all narrowings dilated. Predictors of restenosis of individual narrowings were: higher pre-PTCA percent stenosis (87 +/- 10% in narrowings with restenosis vs 82 +/- 10% in narrowings without, p less than 0.02), and higher degree of residual stenosis after PTCA (46 +/- 13% in narrowings with restenosis vs 36 +/- 12% in narrowings without, p less than 0.001). Balloon size or inflation pressure did not predict recurrence of narrowings. Repeat PTCA was successful in 97% of cases attempted (33 of 34), 3 patients underwent elective bypass surgery and 3 were managed with medical therapy. Most patients with clinical recurrence after PTCA of multiple arteries do not have restenosis of multiple arteries or narrowings, and only one-third will have recurrence of all narrowings.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

Alternative medical treatment for patients with angina pectoris and adverse reactions to beta blockers. Usefulness of nifedipine.

Although beta blockers are effective for the treatment of angina pectoris, chronic adverse effects produced by these agents--including lethargy, fatigue, and male impotence--can adversely affect patient acceptance and treatment compliance. To assess the clinical effects of switching from anti-anginal treatment with beta blocker only (phase I) to half-dose beta blocker plus the calcium blocker nifedipine (phase II) or nifedipine alone (phase III), 18 patients with chronic stable angina pectoris and side effects to beta blockers were evaluated in a 12-week, open-label trial. Three patients did not complete the study, one secondary to new unstable angina and two secondary to nifedipine side effects. Of the 15 patients completing the trial (13 men and two women; mean age, 54 +/- 5 [SEM] years), all sequentially participated in the one-month phases. Weekly angina frequency assessed from patient diaries was significantly less for treatment with nifedipine only (phase III) as compared with beta blocker (phase I) (1.7 +/- 1 versus 3.9 +/- 1 episodes per week), while phase II was not significantly different. Exercise test time was maintained throughout all phases (phase I, 457 +/- 39; phase II, 458 +/- 40; and phase III, 498 +/- 48 seconds, p not significant). All 15 patients in phase I (100 percent) had side effects to beta blockers, but these side effects were lessened in 12 patients (80 percent) in phase II and 13 patients (86 percent) in phase III, with total alleviation of symptoms in two patients (13 percent) in phase II, and eight patients (53 percent) in phase III. Thus, in patients with side effects to beta blockers, switching to nifedipine is associated with a significant reduction in beta blocker adverse symptoms and equal anti-anginal efficacy.

Adrenergic beta-Antagonists↗
PubMed1986

Early and late outcome of percutaneous transluminal coronary angioplasty for subacute and chronic total coronary occlusion.

Percutaneous transluminal coronary angioplasty (PTCA) for nonacute total coronary occlusion was performed in 46 patients, with a 63% primary success rate (29 of 46 procedures). There were no acute myocardial infarctions and no deaths in the study group. There was no difference in success rate according to vessel dilated, prior myocardial infarction, or lesion morphology. The success rate with occlusions less than 2 weeks' duration was 14 of 19 (74%) vs 15 of 27 (55%) with occlusions greater than 2 weeks' duration (p = NS). There was clinical recurrence in 14 of 29 (48%). Factors predictive of recurrence included a greater residual post-PTCA stenosis of 47 +/- 6% in recurrences vs 31 +/- 3% in nonrecurrences (p less than 0.025), while estimated duration of initial occlusion was 1.1 +/- 0.4 months for recurrences vs 3.1 +/- 1 months for nonrecurrences (p = 0.07). PTCA for total occlusion has a lower success rate and higher recurrence rate than PTCA for nontotal stenoses. Recurrence appears to be related to a higher degree of post-PTCA residual narrowing and to a shorter duration of initial occlusion.

Angiography↗
PubMed1985

Acute electrophysiologic, hemodynamic and left ventricular effects of nifedipine and beta-blocker interactions. Maintenance of global and regional left ventricular wall motion.

To assess potential cardiac effects of nifedipine and beta-blocker interactions, 10 men receiving chronic beta-blocker therapy for angina underwent hemodynamic, electrophysiologic and left ventricular (LV) functional analyses at the time of cardiac catheterization before and after buccal administration of 10 mg of nifedipine. Although this combination is usually well tolerated, there have been occasional reports suggesting that the combination of nifedipine and beta-blocking agents may increase the likelihood of congestive heart failure, severe hypotension or exacerbation of angina. All patients had class II or III stable angina pectoris and were receiving at least 160 to 240 mg/day of propranolol or equivalent doses of beta-blocker therapy. Nifedipine produced no acute electrophysiologic changes, including heart rate, PR interval, AH interval, HV interval, sinus node recovery time or heart rate at which atrioventricular nodal block occurred. Hemodynamic effects included no significant change in mean right atrial pressure (7 +/- 1 vs 5 +/- 1 mm Hg), while mean pulmonary artery pressure decreased significantly (20 +/- 2 vs 17 +/- 1 mm Hg, p less than or equal to 0.05). In addition, LV end-diastolic pressure decreased significantly from 16 +/- 2 to 10 +/- 1 mm Hg (p less than or equal to 0.05), with a nonsignificant decrease in mean aortic pressure from 93 +/- 5 to 86 +/- 4 mm Hg. Likewise, no significant change occurred in cardiac index (3.2 +/- 0.4 vs 3.0 +/- 0.4 liters/min/m2) or systemic vascular resistance (1,157 +/- 247 vs 1,170 +/- 236 dynes/s/cm-5). Left ventricular ejection fraction (EF) was the same before and after nifedipine (73 +/- 2% vs 74 +/- 2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1985

Effects of percutaneous transluminal coronary angioplasty on lesion-associated branches.

To assess the effects of percutaneous transluminal coronary angioplasty (PTCA) on lesion-associated branches, angiograms from 100 consecutive angioplasties involving 109 lesion dilatations were analyzed. Ninety-seven lesion-associated branches occurred in 76 (70%) of the dilated stenoses. Sixty-six (68%) branches were small (less than or equal to 1 mm) and 31 (32%) were moderate (greater than 1 mm) in size. Pre-PTCA branch ostial narrowing was present in 52 (54%), whereas there was no ostial disease in 45 (46%). Decreased ostial lumen occurred in 16 (16%) branches following angioplasty. Decreases in branch ostia were significantly more frequent in branches with preexisting branch disease (14 of 52, 27%) compared to branches with normal pre-PTCA ostia (2 of 45, 4%; p less than or equal to 0.01). However, vessel size, PTCA success, gender, and lesion dissection did not predict likelihood of branch ostial changes. Seven branches became totally or subtotally occluded following PTCA, one after unsuccessful and six following successful dilatation. Of the latter six, three experienced chest discomfort and one had an elevated creatine kinase with myocardial band, but no patient had immediate ECG changes. In summary, although moderate- or small-sized branches frequently accompany PTCA lesions, branch changes following angioplasty are infrequent and occur most often in branches with preexisting ostial disease.

Adult↗
PubMed1985

Coronary angioplasty of multiple vessels: short-term outcome and long-term results.

Experience with percutaneous transluminal coronary angioplasty (PTCA) of multiple vessels was reviewed to assess short-term outcome and long-term results. PTCA of multiple vessels was performed in 100 of the initial 500 patients (20%) who underwent PTCA at the Medical College of Virginia between July 1979 and August 1984. Eighty-nine percent had class 3 or 4 angina, and 66% had unstable angina. Two-thirds had severe stenosis of two vessels or major branches and one-third had three-vessel disease. One or more significant lesions were dilated in two vessels in 84 patients, in three vessels in 14 patients, and in four vessels in two patients. PTCA of 273 lesions (2.7/patient) was attempted (range two to eight per patient) with angiographic success in 250 lesions (91.6%). Primary success (angiographic and clinical improvement) was achieved in 95 of 100 patients (95%); 84% had success in multiple vessels, and 79% had success in all attempted lesions. Complications occurred in 11 patients (11%); four patients (4%) underwent urgent bypass surgery and four additional patients (4%) had myocardial infarction. Long-term results were assessed in 44 patients with primary success who had follow-up of more than 1 year (mean 26 months) after multiple-vessel PTCA. Twenty-eight patients (64%) remain event-free and improved and 48% are event-free and asymptomatic. Clinical recurrence developed in 15 patients (34%); four had sustained improvement with repeat PTCA, three remain improved with medical therapy, and eight (18%) have undergone bypass surgery during follow-up. One patient (2.3%) developed late myocardial infarction, and deaths have occurred in the follow-up cohort.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Return to work after coronary angioplasty: a report from the National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

Employment status was analyzed in 2,250 patients enrolled at 65 clinical centers in the NHLBI PTCA Registry. Patients were classified into 3 groups depending on the outcome of PTCA. In 63.6%, PTCA was successful without MI or CABG (Group A); in 25.3%, PTCA was unsuccessful and was followed by CABG (Group B); and in 11.1%, PTCA was unsuccessful and was followed by medical therapy alone (Group C). At entry, 68.3% of all patients were employed full- or part-time. The clinical characteristics of the 3 groups were different. Patients in Group C had a higher incidence of previous MI and previous CABG. In addition, patients in Group C had a significantly decreased baseline employment rate compared with those in Group A. At a mean follow-up of 1.5 years, there was a small but similar decrease in the percentage employed full- or part-time in all groups. Employment status also was analyzed in a subset of 1,150 patients working full- or part-time at baseline and aged 60 years or younger, who would be expected to have the highest return to work rates. At a mean follow-up of 1.4 years, 81 to 86% of patients remained working irrespective of the outcome of PTCA. However, patients with successful PTCA returned to work significantly sooner. The occurrence of chest pain during follow-up in these patients was an important predictor of return to work, irrespective of the outcome of dilatation. In patients with chest pain during follow-up, only 77% were working, compared with 90% of patients who had not had chest pain.

Angioplasty, Balloon↗
PubMed1984

Restenosis after percutaneous transluminal coronary angioplasty (PTCA): a report from the PTCA Registry of the National Heart, Lung, and Blood Institute.

The results of follow-up angiography in patients from 27 clinical centers enrolled in the PTCA Registry were analyzed to evaluate restenosis after PTCA. Of 665 patients with successful PTCA, 557 (84%) had follow-up angiography (median follow-up 188 days). Restenosis, defined as an increase of at least 30% from the immediate post-PTCA stenosis to the follow-up stenosis or a loss of at least 50% of the gain achieved at PTCA, was seen in 187 patients (33.6%). The incidence of restenosis in patients who underwent follow-up angiography was highest within the first 5 months after PTCA. Restenosis was found in 56% of patients with definite or probable angina after PTCA and in 14% of patients without angina after PTCA. Twenty-four percent of patients with restenosis did not have either definite or probable angina. Multivariate analysis selected 4 factors associated with increased rate of restenosis: male sex, PTCA of bypass graft stenosis, severity of angina before PTCA and no history of MI before PTCA.

Angioplasty, Balloon↗
PubMed1984

Combined intracoronary streptokinase infusion and coronary angioplasty during acute myocardial infarction.

PTCA was performed in 28 patients with acute MI immediately after intracoronary streptokinase administration. Indications were failure to obtain reflow in 16 patients and high-grade residual stenosis in 12. PTCA was successful in 11 of 16 cases of streptokinase failure, increasing the overall reflow rate from 66% to 77%. PTCA reduced residual coronary stenosis by more than 20% in 9 of 12 cases in which streptokinase infusion was successful, with 1 acute reocclusion. The frequency of recurrent ischemic events in hospital was 76% in patients with a stenosis of 90% or greater after streptokinase infusion (no PTCA), 14% when residual stenosis was less than 90%, and 6% after successful PTCA. Late restenosis or reocclusion was documented in 5 of 11 PTCA cases (45%). Immediate PTCA after streptokinase administration produces increased clinical stability in hospital, but late restenosis is frequent.

Angioplasty, Balloon↗