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Biomedical subjects

D S Baim

Publications and source records attributed to D S Baim.

At least 181 records · Page 10Linked to original sources
PubMed1989

Effect of phosphodiesterase inhibition on myocardial oxygen consumption and coronary blood flow.

The phosphodiesterase inhibitors (amrinone, milrinone and enoximone) can cause major improvement in the performance of the failing heart without increasing myocardial oxygen consumption. This appears to be the result of a reduction in left ventricular systolic wall stress due to peripheral arteriolar vasodilatation, which offsets the increase in myocardial oxygen consumption that would otherwise result from an enhanced inotropic state. In comparison, catecholamine agents such as dobutamine, given at doses that achieve the same level of inotropic enhancement or improved left ventricular performance, produce less associated arteriolar vasodilatation and a significant (approximately 30%) increase in myocardial oxygen consumption. This difference between the phosphodiesterase inhibitors and the conventional catecholamine agents may be of clinical importance in patients with limited coronary flow reserve due to severe congestive heart failure.

Amrinone↗
PubMed1988

Use of balloon flotation pacing catheters for prophylactic temporary pacing during diagnostic and therapeutic catheterization procedures.

The use of prophylactic temporary pacemakers during diagnostic catheterization, coronary angioplasty and percutaneous balloon valvuloplasty was investigated retrospectively over an 18-month period. Balloon flotation temporary pacemaker leads were placed in 193 (12%) of 1,609 patients undergoing diagnostic catheterization, 641 (65%) of 993 patients undergoing coronary angioplasty and 199 (100%) of 199 patients undergoing aortic or mitral valvuloplasty. There were no perforations or significant arrhythmic complications related to pacemaker placement in these 1,033 cases, and pacing was initiated promptly when required by withdrawal of the catheter tip into the right ventricle. Significant bradycardia or new conduction defects developed in 17 patients (1%) during diagnostic catheterization, 10 patients (1%) during angioplasty and 20 patients (10%) during valvuloplasty, but were severe enough to require initiation of temporary pacing in only 1 (0.06%), 4 (0.4%) and 5 (2.5%) patients, respectively. No patient undergoing diagnostic catheterization or angioplasty (but 5 patients undergoing valvuloplasty) required immediate pacing support to treat a life-threatening bradycardia. The total cost of prophylactic pacemakers was $103,300, with a cost per actual use of $19,300 for diagnostic cases, $16,025 for angioplasty and $3,980 for balloon valvuloplasty. These data suggest that prophylactic temporary pacing is not indicated during either diagnostic catheterization or coronary angioplasty, but should be used routinely during balloon valvuloplasty.

Angioplasty, Balloon↗
PubMed1988

Use of percutaneous transluminal coronary angioplasty: results of a current survey.

To evaluate the current use of percutaneous transluminal coronary angioplasty (PTCA) in the treatment of coronary artery disease, 50 operators experienced in angioplasty (mean experience 949 +/- 706 cases) were surveyed. Although the use of angioplasty is still skewed toward less extensive disease (80% of 1-, 64% of 2- and 39% of 3-vessel disease), it is now estimated that 39 +/- 16% of patients undergoing diagnostic angiography are ultimately referred for PTCA, whereas only 28 +/- 13% are referred to bypass surgery. PTCA thus accounts for 58% of revascularization. Although approximately half of current PTCA patients are clinical candidates for bypass surgery, much of the growth of angioplasty has consisted of treating patients who are either too high a risk for bypass, or who have symptoms with medical therapy that are too mild to warrant surgery. Whereas elective procedures for stable angina (60 +/- 18%) are still the predominant indication for PTCA, a substantial fraction of procedures are performed for unstable angina (27 +/- 10%) or for acute myocardial infarction (13 +/- 15%). Despite a 91% current success rate, 9% of cases are unsuccessful, including 3% in which emergency bypass surgery is required. The most common reasons for unsuccessful procedures are failure to cross the lesion with a wire or balloon (52%), failure to dilate the lesion (4%), and abrupt closure of the dilated segment (44%) due predominantly to extensive local dissection. These data, based on a pooled experience of some 46,000 PTCA procedures, offer a unique glimpse into the current expanded application of this technique.

Angioplasty, Balloon↗
PubMed1988

Initial success and long-term follow-up of percutaneous transluminal coronary angioplasty in chronic total occlusions versus conventional stenoses.

Coronary angioplasty was attempted in 1,074 consecutive patients, including 169 patients with total (100%) occlusion (group 1), 102 patients with functional total (99%) occlusion (group 2) and 711 patients with conventional (70 to 95%) stenoses (group 3). After exclusion of 92 patients with acute myocardial infarction, the mean age of the patients was 57 +/- 12 years, including 727 men (74%) and 255 women (26%). Although there were no differences between groups with respect to anginal symptoms or extent of coronary artery disease, the primary success rate (by lesion) varied according to lesion severity, and was 63%, 78% and 90% for groups 1, 2 and 3, respectively (p less than 0.001). Only 3 patients (1%) with chronic coronary artery occlusion (groups 1 and 2) required emergency surgery because of side-branch occlusion in 2 patients and guidewire fracture in 1 patient, whereas emergency surgery was required in 14 patients (2%) in group 3. Long-term follow-up averaging 19 +/- 11 months was available for 95% of patients. Although the combined likelihood of death or nonfatal myocardial infarction was below 6% for each group at 2 years (difference not significant), the likelihood of death, nonfatal infarction, coronary bypass surgery or repeat percutaneous transluminal coronary angioplasty was higher (41%) in group 1 than in groups 2 (28%) or 3 (28%) (p less than 0.001). Thus, coronary angioplasty can be performed safely and effectively in patients with chronic total occlusion, although neither the primary success rate nor the long-term follow-up are as favorable as in patients with conventional stenoses.

Angioplasty, Balloon↗
PubMed1988

Use of percutaneous transluminal coronary angioplasty and bypass surgery despite improved medical therapy for unstable angina pectoris.

To evaluate current strategies for the management of unstable angina, 104 consecutive patients admitted to the coronary care unit with unstable angina during a 6-month period were followed prospectively. Although 58 patients had symptomatic relief with the initiation of intensive medical therapy, 46 (44%) continued to have episodes of angina despite maximal tolerated triple-drug antianginal therapy as well as aspirin or heparin, or both. In-hospital mortality for the 104 patients was 4%. The incidence of myocardial infarction was 8%, and differed (p less than 0.01) for the medically responsive group (3%) vs the medically refractory group (13%). Based on clinical status and coronary anatomy, patients were referred for either bypass surgery (46%), coronary angioplasty (41%) or continued medical therapy (13%). Choice of therapy varied according to the extent of coronary disease, with coronary angioplasty attempted in 72% of patients with 1-vessel disease, 44% of patients with 2-vessel disease and 7% of patients with 3-vessel disease. Angioplasty was performed with an initial success rate of 88%, and compared favorably with bypass surgery in terms of in-hospital mortality (0 vs 11%), late mortality (2.8 vs 7.7%), freedom from angina (62 vs 69%) and subsequent employment (44 vs 27%) at 18 months follow-up. The favorable results of angioplasty in this prospective observational study suggest that additional randomized trials should be conducted in this important patient group.

Adrenergic beta-Antagonists↗
PubMed1988

Predictors, therapeutic options and long-term outcome of abrupt reclosure.

To ascertain the clinical and procedural factors that relate to the occurrence and management of abrupt reclosure, data on 1,160 consecutive patients who underwent coronary angioplasty between December 1981 and December 1986 were analyzed. Abrupt reclosure occurred in 54 patients (4.7%), developing during the dilatation procedure in 43 patients (80%) and delayed by 11 +/- 2 hours after the procedure in 11 patients (20%). Patients were divided into 3 groups based on subsequent management: (1) 22 patients (40%) in whom the involved vessel was reopened by additional dilatation, (2) 14 patients (26%) in whom the involved vessel was not reopened but the patient was treated medically, and (3) 18 patients (33%) in whom abrupt reclosure was managed by emergency bypass surgery, yielding an overall emergency surgery rate of 1.6%. Patients whose abrupt reclosure was reopened were more likely to have luminal thrombus (54 vs 28%) and less likely to have extensive local dissection after dilatation (14 vs 61%; p less than 0.025) than patients undergoing emergency surgery. Patients treated medically despite continued vessel occlusion were more likely to have collateral blood flow to the occluded zone (54 vs 11%, p less than 0.01) than patients undergoing surgery. While 10 of 18 patients (56%) undergoing emergency surgery sustained a myocardial infarction, all patient subgroups appeared to do well during long-term follow-up.

Angioplasty, Balloon↗
PubMed1988

Vascular complications of percutaneous femoral cardiac interventions. Incidence and operative repair.

Of 7333 patients undergoing percutaneous left-heart catheterization procedures during a seven-year seven-month period, 73 patients (1%) underwent 75 operative repairs of catheterization-related vascular complications. The overall incidence of operative repair varied according to the type of percutaneous femoral artery procedure performed: 0.6% for diagnostic heart catheterization, 0.9% for percutaneous transluminal angioplasty, 5.2% for transfemoral balloon valvuloplasty, and 11.5% for intra-aortic balloon pump placement. This suggests that (1) femoral and iliac artery occlusions can and should be repaired promptly while the patient is under local anesthesia; (2) false aneurysms in this clinical setting can be approached directly through the aneurysm cavity; (3) the diagnosis of false aneurysm or arteriovenous fistula can usually be made on clinical grounds alone, without resorting to angiography; (4) venous or arterial patch angioplasty is the preferred technique for small or severely traumatized femoral arteries; and (5) the necessity for operative repair of these lesions will continue to increase in frequency as percutaneous cardiologic diagnostic and therapeutic interventions are used more widely.

Adult↗
PubMed1988

Percutaneous balloon mitral valvuloplasty in a pregnant woman with mitral stenosis.

A 39-year-old woman with symptomatic mitral stenosis underwent percutaneous mitral valvuloplasty at the end of her first trimester of pregnancy. Balloon dilatation utilizing a double 18-20 mm balloon technique resulted in improvement in mean mitral gradient (16 to 7 mmHg) and in calculated mitral valve area (1.4 to 2.4 cm2), without significant complications and with an estimated radiation exposure to the fetus of less than 0.2 rads. The procedure resulted in disappearance of symptoms of congestive heart failure and allowed for discontinuation of diuretics. The subsequent course of gestation was uncomplicated and a normal baby boy was delivered in the 36th wk. We conclude that percutaneous mitral valvuloplasty may produce successful palliation of symptoms in patients with mitral stenosis during pregnancy.

Adult↗
PubMed1988

Current complications of diagnostic and therapeutic cardiac catheterization.

Data from 2,883 cardiac catheterizations performed during an 18 month period (from July 1986 through December 1987) were analyzed to assess the current complication profile of diagnostic and therapeutic procedures. Procedures performed during the study period included 1,609 diagnostic catheterizations, 933 percutaneous transluminal coronary angioplasties and 199 percutaneous balloon valvuloplasties. Overall, the mortality rate was 0.28% but ranged from 0.12% for diagnostic catheterizations to 0.3% for coronary angioplasty and 1.5% for balloon valvuloplasty. Emergency cardiac surgery was required in 12 angioplasty patients (1.2%). Cardiac perforation occurred in seven patients (0.2%), of whom six were undergoing valvuloplasty, and five (2.5% of valvuloplasty attempts) required emergency surgery for correction. Local vascular complications requiring operative repair occurred in 1.9% of patients overall, ranging from 1.6% for diagnostic catheterization to 1.5% for angioplasty and 7.5% for valvuloplasty. Although the complication rates for diagnostic catheterization compare favorably with those of previous multicenter registries, current overall complication rates are significantly higher because of the performance of therapeutic procedures with greater intrinsic risk and the inclusion of increasingly aged and acutely ill or unstable patients.

Aged↗
PubMed1988

Transcatheter closure of ventricular septal defects.

Between January and October, 1987, we attempted percutaneous transcatheter closure of seven ventricular septal defects (VSD) in six patients; none of the patients was a candidate for operative management. Patients' ages ranged from 8 months to 82 years (6.0-70 kg); diagnoses included postinfarction VSD (n = 4), congenital VSD (n = 1), and postoperative congenital VSD (n = 2). Indications for VSD closure were shock or respiratory failure (n = 5) or multiple episodes of endocarditis (n = 1). Closure was attempted with a Rashkind double umbrella: VSDs were crossed via the left ventricle and a guide wire was advanced to the right heart, snared with a venous catheter, and used to direct a long sheath (and ultimately the double umbrella) across the VSD. We crossed the VSD in all seven attempts, and a 17-mm double umbrella was successfully placed in each VSD. In the first (postinfarction) patient with the largest (12 mm) VSD, the umbrella embolized after 20 seconds to the pulmonary artery (without reducing flow). The other six umbrellas remained in position, either diminishing or abolishing the left-to-right shunts. Postinfarction patients had increasing VSD shunting over the next several days and died; at postmortem, the umbrellas remained well positioned in the septum, with other VSDs present. All three congenital VSDs had absent or diminished shunts after umbrella closure. These preliminary data indicate that transcatheter VSD closure is feasible in selected cases.

Angiography↗
PubMed1988

Total coronary artery occlusion.

Although once believed to be unsuitable for coronary angioplasty, patients with subacute and chronic total occlusions have now emerged as important candidates for this procedure. They account for between 10% and 15% of current angioplasties. With careful attention to patient selection factors (occlusion duration, length, morphology, associated thrombus) and technique (initial use of soft guidewires and low-profile dilatation catheters, confirmation of correct wire position, examination for unsuspected distal disease, prolonged heparinization post-procedure), primary success can be achieved in more than 75% of patients. New equipment and techniques--such as thermal or specialized mechanical angioplasty--may facilitate successful crossing of the remaining 25% of total occlusions. The presence of collateral blood flow to the distal vessel provides an important "safety net" and explains the low incidence of emergency surgery following PTCA in this patient group. Patients undergoing successful PTCA of total occlusions should be watched carefully, given the somewhat higher incidence of abrupt reclosure and late restenosis compared with dilatation of conventional stenoses.

Angioplasty, Balloon↗
PubMed1987

Effects of milrinone on complex ventricular arrhythmias in congestive heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

To determine whether oral milrinone therapy has an effect on complex ventricular arrhythmias in patients with severe congestive heart failure and, if so, whether a change in the severity of complex ventricular arrhythmias after 1 week of milrinone therapy is associated with a change in the mode or frequency of cardiac mortality, a retrospective analysis was performed to determine the frequency of ventricular tachycardia and the density of ventricular couplets on 24-hour ambulatory electrocardiographic recordings performed before and 1 week after initiation of oral milrinone therapy in 74 consecutive patients with New York Heart Association functional class III or IV congestive heart failure. The endpoints of mortality and mode of death were assessed during a mean follow-up of 6 months. In 91% of the patients, 1 week of oral milrinone therapy was associated with no significant change (85%) or a significant decrease (6%) in the density of ventricular couplets and frequency of ventricular tachycardia. However, in 9% of patients the frequency of complex ventricular arrhythmias increased significantly at the end of 1 week of oral milrinone therapy. In this subgroup, neither total cardiac mortality nor the incidence of sudden cardiac death was significantly higher than that in patients with no change or a decrease in complex ventricular ectopic activity.

Adult↗
PubMed1987

Usefulness of percutaneous transluminal coronary angioplasty for unstable angina pectoris after non-Q-wave acute myocardial infarction.

Without revascularization, patients with non-Q-wave acute myocardial infarction (AMI) are predisposed to angina, recurrent AMI and cardiac death. Percutaneous transluminal coronary angioplasty (PTCA) was performed in 68 patients with angina an average of 2.3 months after non-Q-wave AMI (41 anterior, 27 inferior). Mean diameter stenosis was 95%, with collateralized total occlusion of the infarct-related artery in 23 patients. PTCA was successful in 87% (59 of 68), with a mean residual stenosis of 30%. One patient had emergency bypass surgery. Long-term follow-up (average 17 +/- 10 months) was available for 58 of the 59 patients in whom PTCA was successful. Recurrent angina developed in 41% (24 of 58), but was relieved by repeat PTCA in 14, by late coronary artery bypass surgery in 4 and by medical therapy in 6. There was 1 nonfatal AMI, due to progressive disease in a nondilated vessel, and 1 noncardiac death At last follow-up, 46 of 58 patients (79%) were asymptomatic and fully active or employed. Thus, patients undergoing PTCA for angina after non-Q-wave AMI appear to have a relatively high clinical restenosis rate, but with repeat PTCA have a low incidence of subsequent angina, AMI and cardiac death.

Adult↗
PubMed1987

Assessment of the relationship between distal occluded pressure and angiographically evident collateral flow during coronary angioplasty.

The relationship between the presence of collateral filling on the baseline coronary angiogram and the distal occluded pressure obtained during balloon inflation was examined in 83 patients undergoing coronary angioplasty. The patients were divided into three groups: Group I (n = 40) had conventional stenoses (80% to 95% luminal diameter narrowing) without angiographically evident collaterals, group II (n = 22) had conventional stenoses with angiographically present collaterals, and group III (n = 21) had total or functional total occlusions (99% to 100% diameter narrowing) with angiographically evident collateral flow. There was no significant difference in age, sex, vessel distribution, clinical class, residual gradient, or residual percent stenosis following successful angioplasty among the three groups. The distal occluded pressure in group I (18 +/- 5 mm Hg) was, however, significantly lower than the distal occluded pressure in either group II (34 +/- 7 mm Hg) or group III (36 +/- 9 mm Hg) (p less than 0.001). This could not be explained by differences in aortic pressure, since there was no correlation between the mean aortic blood pressure and the distal occluded pressure and since the distal occluded pressure/aortic pressure ratio in group I (0.23 +/- 0.07) was significantly lower than that of group II (0.41 +/- 0.09) or group III (0.41 +/- 0.11) (p less than 0.001). These findings indicate a close correlation between the presence of angiographically evident collateral flow and the distal coronary artery pressure during an angioplasty balloon inflation.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiography↗
PubMed1987

Incidence and management of limb ischemia with percutaneous wire-guided intraaortic balloon catheters.

In 103 patients who underwent placement of 106 percutaneous wire-guided intraaortic balloon catheters between August 1983 and January 1986, all placements were successful and the average duration of counterpulsation was 3.4 +/- 1.6 days. During counterpulsation, 45 patients developed limb ischemia that required premature balloon removal in 29 patients. The development of limb ischemia was significantly related to the presence of diabetes (risk ratio 2.0), peripheral vascular disease (risk ratio 1.9), female gender (risk ratio 1.8) and the presence of a postinsertion ankle-brachial pressure index less than 0.8 (risk ratio 7.9). There was no association between the development of limb ischemia and age, body surface area, balloon size (10.5F/12F) or adequacy of anticoagulation. Fifteen patients underwent vascular surgery for treatment of balloon-related limb ischemia, which was associated with one operative death. Nine patients had persistent limb ischemia (seven asymptomatic, two symptomatic) at the time of hospital discharge. Improvements in wire-guided balloon technology have increased the probability of successful balloon placement over that of surgical placement and have reduced the incidence of major aortic injury, but there is no evidence that these improvements have reduced the incidence of limb ischemia or its sequelae. This should be borne in mind before proceeding with balloon insertion in patients with one or more risk factors for developing limb ischemia.

Aged↗
PubMed1987

Efficacy and safety of sustained (48 hour) intravenous infusions of milrinone in patients with severe congestive heart failure: a multicenter study.

Milrinone is a new bipyridine inotrope that has shown promise in initial clinical testing when administered intravenously or orally. The present multicenter study was designed to evaluate the clinical effectiveness and safety of sustained (48 hour) intravenous infusions of different doses of milrinone, as would be used clinically, in a controlled fashion using invasive hemodynamic monitoring. Entry was limited to adult patients with chronic heart failure of functional class III or IV, with a cardiac index less than or equal to 2.5 liters/min per m2 or a pulmonary capillary wedge pressure greater than or equal to 15 mm Hg, or both. After stable baseline hemodynamic recordings were obtained, milrinone was given as loading (microgram/kg per 10 min) and maintenance infusions (microgram/kg per min) to 189 patients in one of four loading/maintenance dosage regimens: 37.5/0.375 (low dose, n = 26), 50/0.50 (intermediate dose, n = 95), 75/0.75 (high dose, n = 15) and 50/0.25 (lowest dose, n = 53). The lowest dose was shown to be ineffective for maintenance therapy. Effective individual patient responses were defined as greater than or equal to 20% increase in cardiac index or decrease in pulmonary capillary wedge pressure, or both. During early therapy (less than or equal to 3 hour), 99% of patients showed an effective maximal response, and 90% an effective mean response. An effective mean response was observed during days 1 and 2 in 80% of patients, with a positive dose-response trend (69% response, low dose; 80%, intermediate dose; 93%, high dose; day 1). Each loading regimen was effective, with maximal mean response occurring at 15 minutes. Cardiac index initially increased by an average of 24 to 42% for all patients in the three groups, whereas pulmonary capillary wedge pressure decreased by 24 to 33%. Initial decreases in systemic vascular resistance averaged 15 to 31%. Initial changes in heart rate (+4 to +13%) and mean arterial pressure (-2 to -13%) were modest. Significant mean hemodynamic responses were maintained over the 48 hours. Increases in cardiac index for days 1 and 2 averaged 38 and 39% for those completing constant low dose drug, 34 and 37% for intermediate dose and 73 and 44% for high dose. Decreases in pulmonary capillary wedge pressure for all patients averaged 18 to 32% on days 1 and 2, with little dose response. Heart rate changes were modest and variable, averaging -9 to 9%.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗