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Biomedical subjects

Y L Doi

Publications and source records attributed to Y L Doi.

At least 37 records · Page 2Linked to original sources
PubMed1992

Value of dipyridamole thallium-201 imaging in noninvasive differentiation of idiopathic dilated cardiomyopathy from coronary artery disease with left ventricular dysfunction.

The purpose of this study was to noninvasively differentiate in patients with reduced global left ventricular function between those with idiopathic dilated cardiomyopathy (IDC) and coronary artery disease (CAD). Clinical features and findings of dipyridamole thallium-201 imaging in 55 consecutive patients with IDC were compared with those in 77 with CAD. Left ventricular ejection fraction was similar between the 2 groups (34 +/- 16% vs 39 +/- 7%). Patients with IDC had lower incidences of ischemic chest pain (11 vs 79%; p less than 0.0001), electrocardiographic evidence of myocardial infarction (24 vs 82%; p less than 0.0001), and reversible defects (4 vs 57%; p less than 0.0001) than did those with CAD. The lowest percent thallium uptake in the initial imaging was less with CAD than IDC (30 +/- 15% vs 59 +/- 10%; p less than 0.001). Patterns of perfusion defects were classified as: no defects, multiple small defects and large defects. Of patients with IDC, 15 had no defects, 19 had multiple small defects, and 21 had large defects, whereas all those with CAD had large defects (p less than 0.0001). Stepwise discriminant analysis, using chest pain and electrocardiography, revealed sensitivity of 89%, specificity of 87%, accuracy of 88%, and positive predictive value of 83% in the identification of patients with IDC.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Mechanisms of exercise limitation in hypertrophic cardiomyopathy.

To assess the relation of exercise capacity to indexes of systolic and diastolic function in hypertrophic cardiomyopathy, 81 patients underwent two-dimensional echocardiography, technetium-99m equilibrium radionuclide angiography acquired in list mode and maximal, symptom-limited, treadmill exercise testing with measurement of maximal oxygen consumption (VO2 max). VO2 max for the group was 13.9 to 49.3 (mean 25.4) ml/min per kg. Thirty-six patients (44%) achieved less than or equal to 70% of age-predicted VO2 max. Patients with such a degree of limitation were more likely to be in New York Heart Association functional class II or III (23 of 36 vs. 14 of 45; p = 0.005); there was no such relation between VO2 and the incidence and magnitude of rest left ventricular outflow tract pressure gradient greater than 30 mm Hg (11 of 36 vs. 11 of 45; p = NS and 58 +/- 24 vs. 65 +/- 19 mm Hg; p = NS). In the 22 patients with a left ventricular outflow tract gradient, the ratios of peak ejection to peak filling rate and of atrial contribution to left atrial dimension were related to percent of the age-predicted VO2 max (r = 0.49, p = 0.02 and r = 0.54, p less than 0.02). These ratios reflect impaired left ventricular systolic performance and atrial systolic failure, respectively. Stepwise discriminant analysis revealed these two ratios to be the two strongest predictors (p = 0.0001) of patients with a left ventricular outflow tract gradient whose VO2 max was less than or equal to 70% of the age-predicted value (sensitivity 90%, specificity 100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Comparison of clinical, morphological, and prognostic features in hypertrophic cardiomyopathy between Japanese and western patients.

Apical hypertrophic cardiomyopathy appears to be more common in Japan than in the West. Explanations for this difference include variable methods and criteria for the diagnosis. To assess morphological, clinical, and prognostic differences, 45 consecutive Japanese and 45 age- and gender-matched Western patients with hypertrophic cardiomyopathy were evaluated in two referral institutions by the same individuals. The diagnosis of hypertrophic cardiomyopathy was based on the echocardiographic demonstration of unexplained left ventricular hypertrophy. Patients were aged 8 to 64 years (mean 50); there were 66 males and 24 females. The pattern of left ventricular hypertrophy was similar in Japanese and Western patients: asymmetric septal 64 vs. 76%, concentric 22 vs. 13%, and apical 13 vs. 11% (p = NS). The incidence of an echocardiographic or Doppler calculated left ventricular gradient of > 30 mmHg was similar (11 vs. 18%; p = NS). The maximal left ventricular wall thickness was greater in Western patients (23 +/- 7 vs. 20 +/- 4 mm; p = 0.03), but was not different when adjusted for body surface area. Clinical features including incidence of family history and ventricular tachycardia during 24-h ambulatory electrocardiography were similar. During follow-up (4.9 +/- 4.0 years for Western vs. 4.4 +/- 2.0 years for Japanese), disease-related mortality was worse in Western patients (p < 0.05; 10 versus 2 patients). This evaluation, using the same diagnostic methods and criteria, reveals a worse prognosis in Western patients despite a similar clinical and morphological spectrum of hypertrophic cardiomyopathy.

Adolescent↗
PubMed1991

Noninvasive identification of significant narrowing of the left main coronary artery by dipyridamole thallium scintigraphy.

To evaluate the usefulness of dipyridamole thallium scintigraphy with low-level exercise for the identification of left main (LM) coronary artery disease (CAD), 466 consecutive patients with CAD were studied. Thirty-eight patients (8%) had LM stenosis (diameter narrowing greater than or equal to 50%). The LM scintigraphic pattern was present in 9 of 38 patients with LMCAD and 38 of 428 CAD patients without LMCAD (24 vs 9%; p less than 0.005). This pattern was present in 6 of 9 patients with LMCAD without right CAD and in only 3 of 29 patients with LM and right CAD (67 vs 10%; p = 0.0005). Patients with LMCAD had a higher incidence of premature cessation of low-level exercise (53 vs 21%; p less than 0.0001), chest pain (68 vs 48%; p less than 0.02), blood pressure decrease of greater than or equal to 20 mm Hg (44 vs 16%; p less than 0.002) and greater ST depression (0.17 +/- 0.13 vs 0.06 +/- 0.10 mV; p less than 0.001) during dipyridamole loading than patients without LMCAD. Stepwise discriminant analysis revealed that the LM scintigraphic pattern and markers of ischemia during dipyridamole loading best identified (p less than 0.0001) patients with LMCAD without right CAD (sensitivity 67%, specificity 91%), but this predictability is no better than the LM scintigraphic pattern alone. The combination of clinical markers of ischemia during dipyridamole loading and scintigraphic findings of diffuse slow washout, extensive fixed defects and the LM pattern best identified (p less than 0.0001) patients with LM and right CAD (sensitivity 72%, specificity 80%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Prognostic value of thallium-201 perfusion defects in idiopathic dilated cardiomyopathy.

To assess the prognostic significance of thallium-201 perfusion defects in patients with idiopathic dilated cardiomyopathy (IDC), 43 patients underwent thallium scintigraphy in addition to clinical, echocardiographic, angiographic and hemodynamic evaluation. Eleven patients had no significant thallium perfusion abnormality, 19 had multiple small defects and 13 had a large defect. During 3.2 +/- 2.2 years, 14 patients had disease-related mortality. The patients who died had a higher incidence of ventricular tachycardia (71 vs 31%; p less than 0.02), increased cardiothoracic ratio (60 +/- 6 vs 54 +/- 6; p = 0.005), decreased fractional shortening (11 +/- 6 vs 15 +/- 5; p less than 0.05), increased pulmonary wedge pressure (15 +/- 7 vs 10 +/- 6 mm Hg; p = 0.05), increased left ventricular end-diastolic pressure (21 +/- 8 vs 14 +/- 6 mm Hg; p = 0.02) and abnormal thallium perfusion defects (13 of 14 vs 16 of 26; p less than 0.05) compared with survivors. Age, gender, left ventricular end-systolic and end-diastolic dimensions, cardiac index and ejection fraction were not statistically different in the survivors versus the patients who died. Kaplan-Meier survival estimates at 1, 3 and 5 years were 100% in patients without significant perfusion abnormality; 89, 77 and 64%, respectively, in patients with multiple small defects; and 84, 76 and 30%, respectively, in patients with a large defect (p less than 0.025 by log rank test).(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1990

Aortic regurgitation secondary to Behçet's disease. A case report and review of the literature.

Cardiac complications, especially aortic regurgitation, are very rare in Behçet's disease. This report describes a patient with a complicated abnormality of the aortic valve apparatus and severe aortic regurgitation secondary to Behçet's disease. In the literature, flail prolapsed valve, perforated valves and ruptured pseudoaneurysms of the sinus of Valsalva have been reported. Echocardiography may be most useful to detect these anatomically complex abnormalities and therefore to elucidate the cause of aortic regurgitation in Behçet's disease.

Aortic Valve Insufficiency↗
PubMed1988

Takayasu's arteritis and mitral stenosis.

A 44-year-old housewife was found to have coarctation of the abdominal aorta secondary to Takayasu's arteritis. Since she also had mitral stenosis, possible etiological relation between Takayasu's arteritis and mitral stenosis is suspected.

Adult↗
PubMed1987

Myocardial bridging of the left anterior descending coronary artery without relation to the site of hypertrophy in hypertrophic cardiomyopathy.

Myocardial bridging of the left anterior descending coronary artery producing complete systolic occlusion was demonstrated in a patient with hypertrophic cardiomyopathy, who had localized myocardial hypertrophy in the lateral left ventricular wall outside the territory of that artery. Although a cause and effect relationship between systolic compression of the coronary artery and myocardial hypertrophy has previously been postulated in hypertrophic cardiomyopathy, the lack of relation between the site of the myocardial bridging and the region of the left ventricular hypertrophy in our patient suggests that the myocardial bridging of the left anterior descending coronary artery may not be related to the pathogenesis of asymmetric septal hypertrophy.

Adult↗
PubMed1987

Ring-calcification of coronary artery aneurysms in an adolescent.

A 17-year-old asymptomatic boy with a history of Kawasaki disease in infancy was found to have an abnormal ring-calcification as seen in the chest roentgenogram and the electrocardiographic evidence of anteroseptal myocardial infarction. Coronary angiogram revealed aneurysms associated with ring-calcifications in the right coronary artery and subtotal obstruction of the left anterior descending coronary artery. A plain chest roentgenogram may, at times, be useful for identifying coronary aneurysms in patients with a possible history of Kawasaki disease.

Adolescent↗
PubMed1985

Diastolic time during recovery from upright exercise in persons without heart disease.

To assess the relation between heart rate and diastolic time (cardiac cycle minus electromechanical systole) during the recovery period from upright exercise, 12 normal volunteers were studied immediately after and 2 and 5 minutes after exercise in the upright position. Although heart rate was significantly lower at 5 minutes compared with 2 minutes after exercise (106 vs 116 beats/min), there was significant shortening of diastolic time (from 251 to 230 ms) and total diastole per minute (from 28,634 to 24,220 ms/min). The explanation of this phenomenon appears to be disproportionate lengthening of diastolic time at 2 minutes after exercise, which must represent physiologic response due to increased left ventricular filling as well as continuing adrenergic effects, which would be diminished at 5 minutes. This lengthening of diastolic time also would maintain decreased subendocardial blood flow caused by increased end-diastolic volume.

Adult↗
PubMed1984

Systolic time intervals reconsidered. Reevaluation of the preejection period: absence of relation to heart rate.

Within limits, systolic time intervals are reliable reflectors of cardiac status and responses to physiologic and pharmacologic challenges, with various functional correlates. That heart rate (HR) is an important determinant of the duration of systole is well accepted, owing to its effect on left ventricular ejection time (LVET). An independent rate effect on preejection period (PEP) is disputed. Some studies in pooled normal subjects at rest showed some degree of HR-PEP covariance, leading to widespread rate correction in practical use. However, although right atrial pacing showed the expected HR-LVET relation, it consistently failed to show an HR-PEP relation. Systolic time intervals were examined from echocardiograms of a deliberately heterogeneous group comprising 50 consecutively appearing persons with sinus rhythm. There was no HR-PEP covariance (r = 0.23; p = not significant). However, our subjects were otherwise comparable to those of other investigators, in that all other relations in these subjects were as expected from studies in both pooled and paced subjects: HR with LVET (r = -0.74; p less than 0.001), PEP/LVET with ejection fraction (r = -0.85; p less than 0.001), and PEP/LVET with velocity of circumferential fiber shortening (r = -0.65, p less than 0.001). Thus, HR correction of PEP is inappropriate. All other relations are substantiated in routinely encountered, unselected subjects.

Adolescent↗
PubMed1984

Echocardiographic study of left ventricular wall motion in mitral valve prolapse.

A distinct late systolic "dip" in ventricular wall motion is described in patients with mitral valve prolapse. Sixty patients were referred because of clinically suspected mitral valve prolapse. Thirty of these patients had M-mode echocardiograms showing mitral valve prolapse. An abnormal late systolic "dip" in posterior wall motion was present at chordal level in 9 of 30 patients with prolapse but none of 27 patients without prolapse. All of these nine patients had late systolic prolapse and greater mean velocity of circumferential fiber shortening than 21 patients with prolapse but without the "dip" at chordal level (1.6 +/- 0.3 vs 1.3 +/- 0.2, p less than 0.02). Two of these nine patients had several episodes of transient cerebral ischemic attacks. Direct mural compression by the posterior chordae is offered as a possible mechanism for this echographic wall motion finding.

Adolescent↗
PubMed1984

Apical hypertrophic cardiomyopathy and ventricular tachycardia.

Apical hypertrophic cardiomyopathy was originally reported from Japan as one of the subsets of hypertrophic cardiomyopathy without gradient, usually associated with deep T-wave inversion and a spade-like appearance of the left ventricle. Although many reports from Japan have indicated that these patients with apical hypertrophic cardiomyopathy are mostly asymptomatic and have relatively good prognosis, data on serious ventricular arrhythmias are not yet available. Present documentation of ventricular tachycardia in a patient with this disease suggests that at least some of such patients are also at risk of sudden death and that a systematic study for life-threatening arrhythmia by ambulatory electrocardiographic monitoring may be necessary in these cases.

Cardiomyopathy, Hypertrophic↗
PubMed1983

'Pseudo' systolic anterior motion in patients with hypertensive heart disease.

The systolic motion of the mitral apparatus in patients with hypertensive heart disease and hypertrophic cardiomyopathy was studied in order to quantify the difference. Twelve out of 37 patients with severe systemic hypertension were found to have abnormal systolic anterior motion and had significantly small left ventricular end-systolic dimension (P less than 0.05) and greater ejection fraction and mean velocity of circumferential fibre shortening (P less than 0.01 for each) than the other hypertensive patients without abnormal systolic anterior motion. A comparison between systolic anterior motion in 12 hypertensive patients and mild or moderate systolic anterior motion in 28 patients with hypertrophic cardiomyopathy showed a clear cut difference. 'Pseudo' systole anterior motion reached its peak at end-systole when the posterior wall had contracted fully. 'True' systolic anterior motion, however, reached its peak much earlier than maximum movement of the posterior wall--approximately after two-thirds of systole had been completed. At the time of mitral valve opening, 'pseudo' systolic anterior motion had not yet returned to this initial level, whereas 'true' systolic anterior motion returned prior to the opening of the mitral valve. Anterior chordal motion in hyperdynamic ventricle appears to play a role in the production of 'pseudo' systolic anterior motion.

Adolescent↗