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Biomedical subjects

R D Leachman

Publications and source records attributed to R D Leachman.

At least 37 records · Page 2Linked to original sources
PubMed1986

The QS2/QT ratio as an index of appropriate left ventricular response to autonomic and inotropic stimuli.

Dissociation between duration of electrical and mechanical systole has been seen with increase of myocardial shortening velocity or adrenergic activity. We found a decrease of the QS2/QT ratio after exercise in 10 pts with semisitting bicycle maximal exercise test and a normal radionuclide angiogram. No change was seen in 9 patients with a normal study with beta blockade, and in pts with a abnormal radionuclide test, without beta blockade (11 pts). In 19 normal active individuals, a significant QS2/QT decrease (p less than 0.001) was seen after a submaximal exercise treadmill test, which was inhibited by beta blockade. We believe that QS2/QT diminution is suggestive of an increase of the inotropic state of the left ventricle with exercise, produced through adrenergic stimulation. It is not seen either when an ischemic left ventricle cannot adequately respond to exercise or after beta blockade.

Adult↗
PubMed1985

Correlations of systolic time intervals and radionuclide angiography at rest and during exercise.

Systolic time intervals (STI) were correlated with radionuclide angiography studies (RAS) in 57 patients at rest, during maximal semisitting bicycle exercise, and at 4 minutes following the cessation of exercise. Eleven were judged as being free of coronary artery disease (group 1), while 14 had coronary artery disease without (group 2A), and 27 (group 2B) with a previous transmural myocardial infarction. For RAS, resting radionuclide ejection fraction (REF), the changes in REF and end-systolic volume, and the development of a wall motion abnormality at peak exercise were each highly correlated with the presence of coronary disease (p less than 0.001). The accuracy of STI parameters in predicting the presence of coronary disease was poor (less than 60%). Changes in end-diastolic volume (EDV) correlated significantly with PEP/LVET and LVET1 changes following exercise. Moreover, patients with an abnormal (greater than 25%) increase in EDV at peak exercise had a greater increase in LVET1 in the postexercise period (p less than 0.01). We conclude that STI is not accurate enough a predictor of coronary disease or left ventricular function to serve as a useful screening test. Changes in STI parameters appear to be more related to changes in ventricular volume than to ventricular function.

Adult↗
PubMed1985

Hypertrophic cardiomyopathy and associated coronary artery disease.

Eighty-five consecutive patients with hypertrophic cardiomyopathy underwent hemodynamic evaluation and coronary arteriography to determine, in each case, the incidence and importance of coronary artery disease (CAD). Sixteen patients (19%) had >60% narrowing of the luminal diameter of one or more coronary arteries. Our findings revealed that patients with CAD were significantly older (mean, 64 years) than patients without CAD (mean, 42 years) and had a higher incidence of angina pectoris (81% versus 44%). Left ventricular end-diastolic pressures were lower in patients with CAD (mean, 17 mm Hg) than in those without CAD (mean, 23 mm Hg). The electrocardiographic findings were similar in both groups. There was no operative mortality in either group. In five patients with severe stenosis of the left anterior descending coronary artery (>90%), no collaterals to that artery were seen. In two, filling of the narrowed artery appeared slower than usual. Our study indicates that in patients older than 45 years of age with hypertrophic cardiomyopathy, the incidence of CAD is significantly higher, and warrants coronary arteriography prior to consideration for cardiac surgery. In this study, patients with hypertrophic cardiomyopathy and CAD who underwent corrective surgery for hypertrophic cardiomyopathy concomitantly with coronary artery bypass surgery have had low operative and long-term mortality with long-lasting symptomatic improvement.

Journal Article↗
PubMed1984

Restenosis after transluminal coronary angioplasty detected with exercise-gated radionuclide ventriculography.

Forty-one patients were evaluated with exercise-gated radionuclide ventriculography before and within 4 days after successful transluminal coronary angioplasty and 4 to 12 months later. Patients were subgrouped according to the degree of restenosis demonstrated angiographically at 4 to 12 months (Group I [n = 23]: less than or equal to 20%; Group II [n = 10]: greater than 20% but less than 50%; Group III [n = 8]: greater than or equal to 50%). Patients with abnormal findings on gated radionuclide ventriculography (less than 5 point increase in ejection fraction or wall motion deterioration) early after angioplasty were eventually found to have a greater degree of restenosis than were patients with normal findings (41.2 +/- 30.3 versus 19.0 +/- 25.4% restenosis, p less than 0.0001). The accuracy of abnormal radionuclide ventriculography in predicting 50% or greater restenosis was 73% immediately after angioplasty and 77% at the time of follow-up angiography. Gated radionuclide ventriculographic results were abnormal in 5% of Group I patients compared with 75% of Group III patients (p less than 0.01) early after angioplasty; at late follow-up, they were abnormal in 27% of Group I patients compared with 88% of Group III patients (p less than 0.01). Group I patients had a greater increase in ejection fraction than did Group III patients at early (+11.3 +/- 7.5 versus + 3.5 +/- 6.5 points, p less than 0.01) and late (+11.8 +/- 7.8 versus -1.9 +/- 8.7 points, p less than 0.0005) follow-up. It is concluded that gated radionuclide ventriculography is useful in predicting coronary restenosis after transluminal coronary angioplasty.

Aged↗
PubMed1984

Septal myomectomy and mitral valve replacement for idiopathic hypertrophic subaortic stenosis: short- and long-term follow-up.

The long-term results of septal myotomy-myomectomy or mitral valve replacement, or both, were assessed in 36 patients with idiopathic hypertrophic subaortic stenosis who were followed up for 5 to 67 months (mean 48) postoperatively. The mean left ventricular outflow tract gradient at rest decreased postoperatively in all three patient groups. It decreased from 60 mm Hg (range 17 to 160) preoperatively to 3 mm Hg (range 0 to 20) postoperatively (p less than 0.001) in the 13 patients who underwent mitral valve replacement alone, from 69 mm Hg (range 18 to 140) to 35 mm Hg (range 20 to 50) (p less than 0.05) in the 12 patients who underwent myotomy-myomectomy alone and from 89 mm Hg (range 60 to 165) to 3.8 mm Hg (range 0 to 27) (p less than 0.001) in the 11 patients who underwent myomectomy plus mitral valve replacement. The reduction in gradient was more impressive after mitral valve replacement with or without septal myotomy-myomectomy than after septal myotomy-myomectomy alone. There was a marked reduction in symptoms after all three surgical procedures that was long-lasting and independent of the type of operation performed. There was no operative mortality. Postoperative annual mortality rate was 1.6%. Patients with severe congestive heart failure, significantly elevated left ventricular end-diastolic pressure and atrial fibrillation have a less favorable long-term postoperative prognosis. Septal myotomy-myomectomy is recommended as the procedure of choice for the majority of patients with idiopathic hypertrophic subaortic stenosis who require surgery, because it can alleviate symptoms without subjecting patients to the complications of a valve prosthesis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Amiodarone pulmonary toxicity.

Amiodarone therapy for the treatment of arrhythmias has been found to have severe side effects. Although the drug has been prescribed in Europe for more than 20 years, it has only recently been used in the United States as an investigational drug, and has been found to cause pulmonary toxicity, as well as other major side effects. In the following report, a case of pulmonary toxicity caused by Amiodarone was resolved by steroid therapy. A review of the literature suggests that physicians prescribing this medication should be alert to the possibility of pulmonary toxicity.

Journal Article↗
PubMed1984

The accuracy of exercise induced ST segment elevation as a sign of left ventricular aneurysm.

In 3,108 consecutive treadmill exercise tests, ST segment elevation developed or increased over its value at rest in 47 patients (1.5%) in the area of a previous myocardial infarction. Left ventricular angiograms were performed in all cases. A left ventricular aneurysm was found in 39 of the 47 patients (83%), akinesis in four patients (8.5%), and hypokinesis in two patients (4.25%). In two of the 47 patients (4.25%), the diagnosis of hypertrophic cardiomyopathy was made. The ST segment elevation, which is produced or accentuated by exercise, is a sensitive indicator of left ventricular aneurysm and is rarely seen except in cases of abnormal contractility of the left ventricle.

Journal Article↗
PubMed1982

Transluminal coronary angioplasty of the right coronary artery brachial cutdown approach.

Transluminal coronary angioplasty (TCA) of the right coronary artery (RCA) was performed by brachial cut-down approach in 33 patients during a period of 16 months. Flexible-tip guiding catheters were used in all cases. TCA was successful in 27 of 33 patients (81%). The stenosis was reduced in successful cases from a mean of 89% predilatation to 26% postdilatation (P less than 0.001). The systolic pressure gradient across the lesion was reduced from a mean of 49 mm Hg to 4 mm Hg (P less than 0.001). Following successful TCA, patients experienced marked improvement in clinical status, functional capacity, and relief of angina. The complication rate in this study was low. There was no early or late mortality. The most common complication was dissection of the coronary artery occurring in four cases (12%). One patient sustained an acute inferior myocardial infarction. Only one patient required emergency coronary artery bypass surgery. The late follow-up (mean 6 months) angiography was obtained in 17 patients. The stenosis recurred in late follow-up in three cases (18%). Our initial experience revealed that the use of softer guiding catheters by brachial technique offers more selective approach for TCA of RCA lesions and provides better results than percutaneous femoral approach with fixed-tip catheters. Our success rate of 81% for dilatation of RCA is significantly higher than previously reported.

Adult↗
PubMed1982

Intermittent disappearance of a patent ductus arteriosus murmur: report of a case and review of the literature.

A 10-year-old girl with a diagnosis of patent ductus arteriosus from the time of birth was noted to have disappearance of her typical continuous murmur on two separate, well-documented occasions. Cardiac catheterization showed a small patent ductus arteriosus with a pulmonic/systemic flow ratio of 1.3:1. Conservative treatment was advised. Twelve other cases of intermittent disappearance of the murmur of a patent ductus arteriosus were found in the literature.

Journal Article↗
PubMed1982

Aneurysm of the membranous septum causing outflow obstruction of the venous ventricle in corrected transposition of the great arteries.

A 58 year-old man with clinical and hemodynamic evidence of subpulmonic stenosis was admitted to our hospital. Angiography revealed corrected transposition of the great arteries and an aneurysm of membranous ventricular septum (AVS) that protruded into the venous outflow tract, causing severe subpulmonic obstruction during systole. The diagnosis was confirmed at surgery, and successful repair of the aneurysm was performed. This was an unusual case because the AVS caused such severe obstruction that the venous ventricular pressure was elevated to a value equal to the systemic level.

Journal Article↗
PubMed1980

Persistent atrial paralysis: Case report with light microscopy and ultrastructural analyses.

Persistent atrial paralysis in a patient with complete heart block and mild mitral insufficiency is presented. Left atrial specimens obtained during implantation of a permanent cardiac pulse generator showed evidence of hypertrophy and fibrosis; subcellular degenerative changes ranged from near normal to irreversible, thus suggesting that atrial paralysis may be due to the replacement of normal atrial muscle with nonfunctional fibrous tissue.

Journal Article↗
PubMed1979

Major dehiscence of a prosthetic aortic valve: detection by echocardiography.

A 21-year-old man had acute aortic insufficiency three months after insertion of an aortic valve prosthesis. Chest roentgenography demonstrated abnormal orientation of the prosthesis. M-mode echocardiography showed dense, linear echoes from the prosthetic valve between the interventricular septum and the mitral valve, along with loss of normal poppet motion within the aortic root. At surgery, the prosthesis was found to be extensively disrupted, resulting in prolapse into the left ventricular outflow tract. Another valve replacement was performed with patient survival. Echocardiography appears to be a useful adjunct to established roentgenographic procedures in the diagnosis of major dehiscence of prosthetic aortic valves.

Acute Disease↗