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Biomedical subjects

F A Shawl

Publications and source records attributed to F A Shawl.

At least 19 recordsLinked to original sources
PubMed1999

Procedural results and early clinical outcome of percutaneous transluminal myocardial revascularization.

A substantial number of patients present with medically refractory angina who are not candidates for angioplasty or bypass surgery. The creation of channels between the myocardium and the ventricular blood pool has been performed after thoracotomy with excellent relief of symptoms but has been associated with high perioperative mortality. We investigated the safety of a nonoperative, percutaneous technique for channel creation. Twenty-seven patients with angina and coronary anatomy not amenable to revascularization with coronary angioplasty or bypass surgery underwent percutaneous transluminal myocardial revascularization (PTMR). Energy from a Holmium:yttrium-aluminum-garnet (YAG) laser was directed through a fiber enclosed in a catheter to the ventricular myocardium creating channels between the blood pool and the myocardium. On average, 17 +/- 4 channels were formed per patient. There were no procedure-related deaths, episodes of tamponade, or other complications except for an increase in creatine phosphokinase in 1 patient. Immediately after the procedure, there was no worsening of regional wall motion function in any patient, but rather improvement in some. All patients were discharged alive after a hospital stay of 1.8 +/- 1.5 days. Mean Canadian Cardiovascular Society functional class declined from 3.6 +/- 0.5 before the procedure to 0.65 +/- 0.8 at 30 days after the procedure (p < 0.01). For 12 patients eligible for 6-month follow-up, mean functional class was 0.94 +/- 0.97. At 6-month stress testing, 9 of these 12 had no electrocardiographic evidence of ischemia. Thus, PTMR can be performed safely in the cardiac catheterization laboratory with a complication rate lower than that reported in surgical series and with excellent near-term symptomatic relief. The long-term effect of PTMR on mortality and relief of angina as well as its safety and effectiveness compared with the surgical approach remains to be defined.

Aged↗
PubMed1998

Percutaneous techniques for the treatment of cerebrovascular disease.

Stroke is the third leading cause of death in the United States. Carotid artery stenting is being investigated as a therapeutic strategy for the management of extracranial bifurcation stenosis and has the potential to prevent stroke in thousands of patients. Carotid endarterectomy, although effective, does have limitations, and percutaneous techniques may offer an alternative method of treatment, especially for those who are at highest risk. Although the technique is still evolving, this article describes the protocol and technique of stent-supported carotid angioplasty and care for patients undergoing this procedure at Washington Adventist Hospital in Takoma Park, MD.

Aged↗
PubMed1998

Percutaneous cardiopulmonary support for high-risk angioplasty.

Treatment of patients with coronary artery disease with severe left ventricular dysfunction (EF less than 25%) presents a special challenge to the health care team. The ability to revascularize coronary artery lesions using percutaneous transluminal coronary angioplasty is limited because of the risk of acute vessel closure, which can result in hemodynamic collapse, myocardial infarction, and the need for emergent coronary bypass surgery. These patients may not survive long enough to undergo emergency open-heart surgery if acute vessel closure occurs. Percutaneous cardiopulmonary support (PCPS), initiated in the catheterization laboratory before coronary revascularization, can provide the hemodynamic support needed to allow the patient to tolerate the high-risk procedure. This article describes the PCPS procedure at Washington Adventist Hospital, Takoma Park, MD, and includes the clinical applications, risks and benefits, and implications for the critical care nurse.

Angioplasty↗
PubMed1996

Percutaneous cardiopulmonary bypass-supported coronary angioplasty in patients with unstable angina pectoris or myocardial infarction and a left ventricular ejection fraction < or = 25%.

The objective of this study was to determine the acute and long-term results of percutaneous cardiopulmonary bypass-supported angioplasty in treating high-risk patients with unstable presentations and severely depressed left ventricular (LV) function (ejection fraction [EF] < or = 25%). One hundred seven consecutive patients with a mean LVEF of 19 +/- 3% were studied. Seventy-four patients (69%) had unstable angina, 60 (56%) had New York Heart Association class III or IV symptoms, 74 (69%) had recent (< 15 days) documented acute myocardial infarction, 103 (96%) had 3-vessel disease, and 58 (54%) had only 1 remaining patent artery. A total of 50 patients (47%) were deemed unsuitable for bypass surgery. Of 196 severe narrowings attempted in 166 coronary arteries, 193 (98%) were successfully dilated in 105 patients (98%), and there was no procedure-related mortality, Q-wave myocardial infarction, or urgent requirement for coronary bypass surgery. There were 5 in-hospital deaths (4.7%) and the remaining 102 patients have been followed for 24.5 +/- 1.3 (mean +/- SE) months. Twenty-three patients (21%) died between 1 and 23 months after the procedure. One- and 2-year survival free of cardiac death was 83% and 77%, respectively. Of the 79 surviving patients, 65 have survived event free of myocardial infarction and revascularization; event-free survival for 1 and 2 years was 76% and 69.5%, respectively. In the 64 patients in whom LV function was measured before and after the procedure, global EF increased from 20.6% to 29.3% (p < 0.001). Patients who remained event free had a greater improvement in LVEF than those who had a cardiac event during follow-up (p < 0.05). Thus, this study demonstrates the safety and efficacy of percutaneous cardiopulmonary bypass-supported angioplasty in the immediate treatment of high-risk unstable patients with multivessel coronary artery disease and severely depressed LV function.

Actuarial Analysis↗
PubMed1994

Role of percutaneous cardiopulmonary bypass and other support devices in interventional cardiology.

Percutaneous cardiopulmonary bypass support has a role to play in the management of the high-risk coronary angioplasty patient. This article discusses the basic principles of cardiopulmonary bypass, technique, indications, and complications of this new addition to interventional cardiology. In addition, the role of other support devices during high-risk coronary interventions is also discussed.

Angioplasty, Balloon, Coronary↗
PubMed1993

Minimally invasive angioplasty: acute and long term results of low pressure dilatation with a non-compliant balloon during percutaneous transluminal coronary angioplasty.

Despite technological advances in angioplasty equipment and increased operator experience, the incidence of dissection and abrupt closure remains unchanged. To test the hypothesis that a different balloon inflation strategy may influence the degree of arterial trauma, and therefore reduce the incidence of major complications, the success rate, acute complications and incidence of restenosis were analyzed in 110 consecutive patients using a non-compliant dilatation catheter. The term "minimally invasive angioplasty" has been coined to describe a strategy of minimizing arterial trauma by using the lowest possible inflation pressures during percutaneous transluminal coronary angioplasty (PTCA). Lesion analysis using a modified American College of Cardiology/American Heart Association Classification showed that 37% of lesions were Type A, 40% were Type B, and 23% were Type C. Overall, PTCA success was achieved in 98% of lesions. Major dissection and abrupt closure occurred in 1%. No patient required emergency coronary bypass surgery and there were no deaths. The mean coronary stenosis was reduced from 85% to 18.4%. In 75% of lesions, inflation pressures of 5 atmospheres (atm) or less were used. Angiographic follow-up was available in 80 (73%) of the patients and restenosis occurred in 19 (24%). Thus, minimally invasive angioplasty, a technique which may reduce arterial trauma, results in a high primary success rate; low residual stenosis; and very low incidence of abrupt closure, major dissection and perhaps lower restenosis. These data suggest the need for further study of PTCA techniques designed to minimize arterial trauma.

Aged↗
PubMed1991

Demonstration of myocardial reperfusion injury in humans: results of a pilot study utilizing acute coronary angioplasty with perfluorochemical in anterior myocardial infarction.

Reperfusion may limit the amount of potentially salvageable myocardium through the introduction of cellular elements into previously ischemic but viable myocardium (reperfusion injury). It has been demonstrated that intracoronary infusion of a 20% intravascular perfluorochemical emulsion (Fluosol) significantly reduces infarct size and results in improved left ventricular function in the canine model. This pilot study was performed to explore the existence of myocardial reperfusion injury in humans. Utilizing Fluosol as a probe in conjunction with emergency coronary angioplasty, 26 patients presenting within 4 h with a first anterior myocardial infarction were randomized to emergency angioplasty or angioplasty followed by a 30-min intracoronary infusion of Fluosol at 40 ml/min. Global and regional ventricular function were assessed immediately and a mean of 12 days after successful angioplasty with contrast ventriculography. Infarct size was semiquantitated with thallium-201 single-photon emission computed tomography (SPECT) images before discharge. Twelve patients (six undergoing angioplasty alone, six treated with angioplasty and Fluosol) had an occluded infarct-related vessel (Thrombolysis in Myocardial Infarction [TIMI] grade 0 to 1) at the time of emergency catheterization and were included in the final analysis. At 12 days after successful angioplasty, the improvement in regional ventricular function was greater in patients receiving adjunctive therapy with intracoronary Fluosol versus those undergoing angioplasty alone utilizing both the radial shortening and centerline method, respectively (23 +/- 3.1% vs. 8 +/- 2.3%, p less than 0.02; and -1.6 +/- 0.4 vs. -2.9 +/- 0.2 SD/chord, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

Emergency cardiopulmonary bypass support in patients with cardiac arrest in the catheterization laboratory.

Cardiac arrest in the catheterization laboratory is fatal if unresponsive to advanced cardiac life support (ACLS). Seven patients not responding to ACLS following cardiac arrest in the catheterization laboratory underwent percutaneously instituted cardiopulmonary bypass support. Cardiac arrest occurred following abrupt closure postcoronary angioplasty in three patients, during cardiogenic shock in three patients, and during diagnostic angiography in one patient. Cardiopulmonary bypass was instituted 10-45 min (mean, 21 min) following the onset of cardiac arrest. Flows on bypass ranged from 4.0 to 5.2 liter/min. Mean blood pressure ranged from 70 to 110 mm Hg on bypass. Six of the seven patients regained consciousness after the institution of bypass. Acid-base balance was normalized in all patients. Coronary bypass surgery was subsequently performed in three patients and coronary angioplasty in two. Four patients survived. One patient died following coronary bypass surgery. Two patients, who were not suitable candidates for revascularization, expired. Total bypass time was 1.5-8.5 hr (mean, 2.7 hr). At a mean follow-up of 6 months, all four survivors are alive and asymptomatic or NYHA class 1. We conclude that cardiopulmonary bypass support 1) can stabilize patients following cardiac arrest in the catheterization laboratory, 2) can facilitate emergency coronary angioplasty or transfer to the operating room for coronary bypass surgery, and (3) can improve survival in patients unresponsive to ACLS when instituted early following cardiac arrest in the catheterization laboratory.

Aged↗
PubMed1990

Left ventricular rupture complicating percutaneous mitral commissurotomy: salvage using percutaneous cardiopulmonary bypass support.

Left ventricular rupture resulting in death has been reported to be a complication of percutaneous mitral commissurotomy. We report a 71-year-old man in whom a left ventricular rupture occurred during percutaneous mitral commissurotomy and resulted in hemodynamic collapse due to acute cardiac tamponade. The patient was stabilized using percutaneously instituted cardiopulmonary bypass support with subsequent repair of the left ventricle and successful mitral valve replacement. Three months later this patient remains in New York Heart Class I.

Aged↗
PubMed1990

Percutaneous cardiopulmonary bypass support in the catheterization laboratory: technique and complications.

A safe and easily applied technique of percutaneous cardiopulmonary bypass support has been developed for use in the cardiac catheterization laboratory. The importance of this technique lies in its ability to maintain hemodynamic stability during high risk interventional procedures regardless of intrinsic cardiac function. Venous and arterial cannulas (18F) are inserted percutaneously over a stiff guide wire after sequential dilatation with 12F and 14F dilators. Bypass flow rates of up to 5 L/min can be achieved. This technique can be applied to support patients with cardiac arrest, hemodynamic collapse after abrupt closure during coronary angioplasty, and cardiogenic shock, as well as those undergoing high-risk elective coronary angioplasty. This form of support also permits transport of the patient to the operating room in a stable condition after an unsuccessful angioplasty. The complications are mostly related to cannula removal and can be minimized by the use of a proper technique. Although the ultimate role of this new technique remains to be completely defined, it appears that it will expand the patient population for whom coronary interventions can be applied.

Angioplasty, Balloon, Coronary↗
PubMed1990

Effect of coronary angioplasty on electrocardiographic changes in patients with unstable angina secondary to left anterior descending coronary artery disease.

The effect of semiemergent percutaneous transluminal coronary angioplasty on clinical and electrocardiographic (ECG) variables was assessed in 76 patients with unstable angina secondary to an isolated severe proximal left anterior descending coronary artery stenosis. All patients manifested symmetric T wave inversion in two or more anterior ECG leads. Wall motion abnormalities were present in 37 patients on ventriculography before dilation. Angioplasty was successful in 70 patients (92%), resulting in a reduction in luminal diameter stenosis from 91 +/- 8% to 21 +/- 6%, with no major acute procedure-related complications observed. The other six patients underwent semiurgent (less than 48 h) coronary artery bypass surgery and three patients experienced a myocardial infarction (before bypass surgery in two). Serial ECGs revealed complete resolution of ST-T wave changes in 51% of patients at 14 weeks and in 90% at 28 weeks. In contrast, prolongation of the corrected QT interval, which was present in 16 patients (8%), normalized within 48 h of successful angioplasty. Twelve of these 16 patients with a prolonged QT interval had nonocclusive thrombus formation and poor collateral circulation on angiography. Patients were followed up for 6 to 43 months (mean 23 +/- 10). Angiographic evidence of restenosis was present in 34% of patients, all of whom underwent a successful second or third procedure. One death occurred at 8 months after successful angioplasty. Wall motion abnormalities had completely resolved in 13 of 15 patients who underwent repeat ventriculography, at which time 10 had a normal ECG. This study demonstrates that ECG changes may persist for up to 7 months in patients who undergo successful angioplasty for severe left anterior descending coronary artery disease and unstable angina. Semiemergent angioplasty was associated with a high initial success rate and excellent long-term outcome.

Adult↗