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Biomedical subjects

W H Willis

Publications and source records attributed to W H Willis.

13 recordsLinked to original sources
PubMed1988

Transfemoral coronary arteriography via a prosthetic aortic bifurcation graft.

Angiographers may inappropriately avoid the transfemoral access route when a prosthetic aortic bifurcation graft exists. An aortofemoral graft will necessitate overdilatation of the femoral puncture site to allow adequate manipulation. If the puncture transverses both walls of the femoral limb of the graft into the native artery, further withdrawal of the catheter will allow reentry into the graft. When an aorta-to-external-iliac, end-to-side graft is present, transfemoral catheterization will frequently result in the guide wire or catheter tip terminating in the occluded common iliac artery. By choosing the proper catheter, entrance into the distal limb of the proximally communicating graft may be achieved. For the unwary operator, these confusing situations may result in failure to properly catheterize the graft. The methods of successfully overcoming these problems are discussed and illustrated.

Aorta, Abdominal↗
PubMed1985

A new femoral bypass graft catheter.

A three-dimensional left coronary bypass graft catheter with a sidewinder configuration is described. It is best suited for superior origins of left coronary bypass grafts. This graft catheter has been used successfully from the femoral route in more than 620 patients without serious complications. The method for using this catheter from the femoral route is described.

Catheterization↗
PubMed1983

Percutaneous transluminal angioplasty of a large septal artery.

A severely stenotic, large-caliber, first septal artery was successfully dilated in a patient with refractory angina and nonsurgical, multivessel coronary artery disease. The success of this dilatation was related to favorable coronary anatomy and to the availability of a guidewire-directed dilatation catheter. Septal artery stenosis with or without surgically accessible stenoses in other coronary vessels represents a potential indication for percutaneous transluminal coronary angioplasty.

Angioplasty, Balloon↗
PubMed1983

Detection of diastolic left ventricular function abnormalities in patients with coronary artery disease and normal systolic function.

We angiographically calculated left ventricular (LV) filling in 50 patients, all of whom had normal systolic LV function and 21 (42%) of whom had coronary systolic LV function and 21 (42%) of whom had coronary artery disease. Five volume determinations were made: at end systole (ESV), first third (DV 1/3, half (DV 1/2), and second third of diastole (DV 2/3), and at the end of diastole (EDV). To assess different modalities of filling, we calculated filling fractions in the first third (FF 1/3) as the ratio of volume filled in the first third diastole (DV 1/3-ESV) over total diastolic filling (EDV-ESV). Similar filling fractions (FF) were calculated at half (FF 1/2), second third (FF 2/3), and last third (FF 3/3) of diastole. We found significant differences between normal and coronary artery disease patients as follows: FF 1/3: 37.4 +/- 14.9 versus 23.8 +/- 11.9%, respectively (p less than 0.002); FF 1/2: 58.6 +/- 14.7 versus 45.3 +/- 15.1% (p less than 0.005); FF 2/3: 33.8 +/- 15.2 versus 39.0 +/- 10.4% (NS), and differences in the opposite direction in the FF 3/3: 28.8 +/- 15.2 versus 37.2 +/- 11.9% (p less than 0.02), respectively. We conclude that LV filling is accomplished differently in patients with coronary artery disease even if they have normal systolic function.

Adult↗
PubMed1980

Coronary arteriograms and myocardial scintigrams in the electrocardiographic syndrome of septal fibrosis.

Coronary artery disease (CAD) and myocardial perfusion were assessed by arteriograms and scintigrams (Technetium-99 microspheres alone or combined with Iodine-131 albumin macroaggregates) in 178 angina pectoris patients with and without the electrocardiographic (ECG) syndrome of septal fibrosis and with greater than or equal to 70% obstruction in one or more coronary arteries. The ECGs of 96 patients without angiographic evidence of obstructive CAD were also examined for the ECG syndrome of septal fibrosis. Patients with the ECG syndrome of septal fibrosis have significantly higher incidences of positive exercise stress test, of greater than or equal to 70% narrowing of the proximal left anterior descending (LAD) artery, of severe proximal LAD disease, and of more extensive left ventricular hypoperfusion than patients without the ECG syndrome. The fact that only 4% of patients without obstructive CAD have the ECG syndrome of septal fibrosis indicates the usefulness of the syndrome in identifying a subset of angina pectoris patients with advanced CAD of the proximal LAD and diffuse left ventricular hypoperfusion.

Angina Pectoris↗
PubMed1980

Clinical and pathologic features of obstructive disease in the predominant right and left coronary circulations in man.

The clinical features and the location and severity of obstructive coronary artery disease are contrasted in 98 patients with predominant left and 99 patients with predominant right coronary circulations. A significantly higher incidence of ventricular conduction disturbances and a greater incidence and severity of obstructive coronary artery disease (greater than or equal to 70% cross-sectional narrowing in the proximal left anterior descending, circumflex and right coronary arteries and their major branches) distinguish the predominant left from the predominant right coronary circulation. The results suggest an anatomically disadvantaged status for the predominant left compared with the predominant right coronary circulations with respect to ventricular conduction disturbances and to coronary atherogenesis in man.

Arterial Occlusive Diseases↗
PubMed1976

Hemodynamic effects of isosorbide dinitrate vs nitroglycerin in patients with unstable angina.

The hemodynamic response to nitroglycerin administration, to sublingual or oral administration of isosorbide dinitrate, or to a placebo was evaluated and compared in 37 patients with unstable angina pectoris under resting, pain-free conditions. Patients with congestive heart failure were not included in this study. Serial measurements of mean arterial blood pressure (MAP), pulmonary arterial end-diastolic pressure (PAEDP), cardiac index (CI), and heart rate (HR) were obtained for one hour following nitroglycerin administration and for four hours following sublingual or oral administration of isosorbide dinitrate. Echocardiographic end-diastolic volume (EDV) measurements were obtained for the groups receiving isosorbide dinitrate or placebo. There was a significant (P less than 0.05 or less than 0.1) reduction of the MAP (5 to 10 mm Hg) that persisted for more than four hours following both sublingual and oral administration of isosorbide dinitrate. The changes in the PAEDP, HR, and CI following sublingual or oral administration of isosorbide dinitrate were small and not significant. In the group receiving isosorbide dinitrate sublingually, the EDV was reduced by more than 30 ml below the placebo group (P less than 0.1) for up to four hours. The effects of nitroglycerin administration were similar in magnitude but of much shorter duration (three to four hours for sublingual and oral administration of isosorbide dinitrate vs 15 to 30 minutes for nitroglycerin). These data demonstrate that the duration of the hemodynamic effects of sublingually and orally administered isosorbide dinitrate in patients with unstable angina pectoris and normal resting hemodynamics is 8 to 12 times longer than that of nitroglycerin.

Administration, Oral↗
PubMed1975

Cardiac disease in Malawi.

A prospective clinical study of 114 Malawian patients with cardiac disease seen at Queen Elizabeth Central Hospital, Blantyre, is presented. Rheumatic and hypertensive heart disease, cardiorenal failure and severe anaemia were the most common causes. Pericardial disease, mainly due to tuberculosis, was an important treatable cause of cardiac disease. Endomyocardial fibrosis was not diagnosed with certainty and cardiomyopathy was relatively uncommon. Ischaemic heart disease was not seen.

Adolescent↗