Search PubMed⌕ Search

Biomedical subjects

M D Cheitlin

Publications and source records attributed to M D Cheitlin.

At least 73 records · Page 4Linked to original sources
PubMed1990

Risk of ventricular arrhythmias in hypertensive men with left ventricular hypertrophy.

The echocardiographic predictors of ventricular arrhythmias are reported for the Hypertension Arrhythmia Reduction Trial. Men with mild hypertension were withdrawn from their diuretic therapy and repleted with 40 mEq/day of oral potassium and 20 mEq/day of oral magnesium for 1 month. M-mode echocardiography and 24-hour continuous ambulatory electrocardiography were performed on 123 men, mean age 62 years. Forty-eight men (39%) had echocardiographic evidence of left ventricular (LV) hypertrophy defined as an LV mass index greater than 134 g/m2 and this finding was not related to the presence of LV hypertrophy on electrocardiogram or to age. Men who had echocardiographic LV hypertrophy were more likely than men without echocardiographic LV hypertrophy to have greater than or equal to 30 ventricular premature complexes (VPCs)/hr (odds ratio = 2.7; 95% confidence interval = 0.9, 8.0), multiform extrasystoles (odds ratio = 1.7; confidence interval = 0.8, 3.7), episodes of ventricular tachycardia (odds ratio = 2.3; confidence interval = 0.7, 7.1) and the combination of frequent (greater than or equal to 30 VPCs/hr) or complex (ventricular couplets, multiform extrasystoles or episodes of ventricular tachycardia) ventricular arrhythmia (odds ratio = 1.7; confidence interval = 0.8, 3.5). Similar associations between echocardiographic LV hypertrophy and ventricular arrhythmias were observed on 24-hour tracings obtained on entry to the study (before electrolyte repletion) in the 96 men who were taking diuretics at this time. The combination of a frequent or complex arrhythmia was also more common in men aged 60 to 70 compared to men aged 35 to 59 (odds ratio = 3.4; confidence interval = 1.4, 8.2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Ethics in cardiovascular medicine. Task Force II: The relation of cardiovascular specialists to patients, other physicians and physician-owned organizations.

1. The American College of Cardiology acknowledges the continuum of changing societal, medical and economic perspectives affecting traditional medical ethics. Primacy of patient responsibility remains paramount to the cardiovascular specialist who at the same time should participate in the development of broader societal programs. 2. Medical decisions should be freely and jointly formulated by the patient and the cardiovascular specialist with appropriate sensitivity to such matters as mental competence, pertinent medical information and standards of care, sufficient time for contemplation, informed consent, patient right of refusal, physician right to refuse to provide inappropriate care and the right of patient, physician or third party payer to seek consultation or additional opinions. 3. The cardiovascular specialist should make a special effort to clarify and document patient preferences regarding end-of-life treatment through some form of advance directive. 4. The cardiovascular specialist bears a moral obligation to provide medical care to any patient who is HIV positive or has AIDS. 5. A conflict of interest occurs when a cardiovascular specialist places personal or financial interest ahead of the welfare and health of a patient. Professional accountability should be established through local or regional peer review. 6. The American College of Cardiology encourages and supports a renewed dedication to the principles of medical ethics, particularly in the field of cardiovascular disease. Cardiovascular specialists are encouraged to participate in the promulgation of medical ethics by teaching and by example, individually and with others.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Comparison of cine MR imaging with Doppler echocardiography for the evaluation of aortic regurgitation.

Regurgitant blood flow is associated with localized signal loss of the blood pool within the recipient chamber on cine MR images, which may be useful for assessing regurgitant valvular disease. To evaluate the potential of this technique for determining the severity of aortic regurgitation, multilevel cine MR imaging was performed in 10 normal volunteers and in 25 patients with aortic regurgitation documented and graded for severity by Doppler echocardiography. Cine MR images were analyzed to obtain cardiac chamber volumes and to measure the extent of the signal loss associated with regurgitation. All regurgitant lesions were visualized on cine MR images as areas of diastolic signal loss extending from the aortic valve into the left ventricle. The extent of signal loss and the regurgitant volume determined from analysis of MR images correlated with the echocardiographic severity of the lesion. The total area of diastolic left ventricular signal loss was 0 cm2 in 10 normal volunteers, 24 +/- 13 (+/- SD) cm2 in eight patients with mild aortic regurgitation, 49 +/- 11 cm2 in nine patients with moderate aortic regurgitation, and 62 +/- 20 cm2 in eight patients with severe aortic regurgitation (p less than .05 for moderate and severe vs mild). Left ventricular volumes calculated from MR images correlated well with echocardiographic volumes (r = .92, SEE = 30 ml, p less than .0001). Regurgitant fraction calculated from analysis of cine MR images was 4 +/- 7% in normal volunteers and 31 +/- 8% in mild, 45 +/- 11% in moderate, and 56 +/- 9% in severe aortic regurgitation (p less than .05 for moderate and severe vs mild and normal). Thus, cine MR imaging can provide useful qualitative and quantitative data regarding cardiac dimensions and regurgitant valvular flow in patients with aortic regurgitation.

Adult↗
PubMed1988

Segmental evaluation of left ventricular wall motion after myocardial infarction: magnetic resonance imaging versus echocardiography.

To assess relative capabilities of magnetic resonance (MR) imaging and two-dimensional echocardiography (2DE) for evaluating regional contractile dysfunction in the left ventricle after a myocardial infarction, results from 22 concurrent MR (orthogonal-transaxial, ECG-gated, multiphasic, single-spin echo) and 2DE examinations were compared. By means of the same 11-segment LV description, MR and 2DE examinations were independently scored segment by segment for residual wall motion (point scores: 2 = normal, 1 = hypokinesia, 0 = akinesia, and -1 = dyskinesia). Significant correlation between MR and 2DE scoring was found throughout most of the left anterior descending (LAD) distribution, but right coronary artery (RCA) distribution (i.e., middle-posterior segment not well seen) could not be fully evaluated by MR imaging. When cumulative scores for the 10 segments mutually evaluated were used to derive measures of global residual LV function (i.e., score quotient [SQ] = accumulated points divided by 20 total possible points), MR SQ correlated well overall with both 2DE SQ (r = 0.82; p less than 0.05) and ejection fraction (EF) from ventriculography (r = 0.86, p less than 0.05 vs r = 0.88, p less than 0.05 for 2DE SQ compared with EF). MR evaluation of segmental wall motion was relatively stronger in the LAD distribution (MR SQ compared with 2DE SQ: r = 0.86, p less than 0.05; MR SQ compared with EF: r = 0.96, p less than 0.05) than in the RCA distribution (r = 0.06, p greater than or equal to 0.05 and r = 0.62, p greater than or equal to 0.05, respectively). For 2DE, regional variations were not as evident (2DE SQ compared with EF: r = 0.90, p less than 0.05 for LAD and r = 0.81, p less than 0.05 for RCA). For segmental evaluation of wall motion after myocardial infarction, MR imaging (transaxial, multiphasic) appears to be comparable to 2DE overall but superior in LAD distribution and inferior in RCA distribution.

Adult↗
PubMed1988

Estimation of the functional and anatomic extent of myocardial infarction using magnetic resonance imaging.

This study assesses magnetic resonance (MR) imaging for the evaluation of both the functional and anatomic extent of damage to the left ventricle (LV) from myocardial infarction (MI). This was accomplished by blinded region-of-interest analysis of 36 MR examinations (orthogonal-transaxial, electrocardiographically-gated, multiphasic, single spin-echo) for determination of ejection fraction (EF) and relative MI volume (i.e., percent of total LV myocardial volume). Comparison of the results was then made with a measure of global residual LV function (i.e., score quotient or SQ) derived from segmental scoring of LV wall motion on a two-dimensional echocardiogram (Echo) and with an EF value from a left ventriculogram (LVG), both performed relatively concurrently with MR. Significant (p less than 0.01) overall correlations were noted between MR-EF and both Echo-SQ (r = 0.56) and LVG-EF (r = 0.78), and these relationships were relatively stronger when MI was located in the right coronary artery (RCA) than when it was found in the left anterior descending (LAD) distribution (e.g., MR-EF compared with LVG-EF: r = 0.87, p less than 0.05 for RCA; and r = 0.48, p = NS for LAD). The best expression of relative MI volume appeared to be based upon absolute volume of regionally-thinned LV wall multiplied by a correction factor for its residual contractility and then the addition of a volume correcting for the amount of regional wall thinning by necrosis (i.e., "total-Fxn" MI volume).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Mitral or aortic regurgitation: quantification of regurgitant volumes with cine MR imaging.

A new, rapid magnetic resonance (MR) imaging method, cine MR imaging, was used to determine the regurgitant fraction (RF) in patients with left-sided regurgitant lesions. Right and left ventricular stroke volumes were determined with cine MR imaging and a modified Simpson formula in ten healthy volunteers and 23 patients known to have either predominant mitral (n = 17) or aortic (n = 6) regurgitation. RFs evaluated at cine MR imaging were compared in healthy persons and patients with mild, moderate, or severe regurgitation demonstrated at angiography (n = 10) and Doppler echocardiography (n = 13). Cine MR imaging depicted regurgitant blood flow in all 29 regurgitant lesions in 23 patients as areas of low signal intensity within the regurgitant chamber. The RF was 4% +/- 7% in healthy subjects and 12% +/- 12% in those with mild, 35% +/- 14% in those with moderate, and 63% +/- 5% in those with severe regurgitation. The RFs determined by two observers were similar.

Adult↗
PubMed1988

Non-Q-wave infarction: diagnosis, prognosis, and treatment.

The patient with a non-Q-wave myocardial infarction should be considered as having an uncompleted myocardial infarction. The ultimate prognosis in this patient depends upon the amount of viable myocardium still at risk. These patients have a higher incidence of reinfarction than those who had a Q-wave infarction. There is evidence that diltiazem after a non-Q-wave infarction can prevent early reinfarction. It is evident that those patients who continue to have myocardial ischemia, manifested by continued angina, ischemia, ST depression, or thallium 201 perfusion defects on exercise, especially if they already have reduced ventricular function, are at the greatest risk. These are the patients who should be considered for angiography and revascularization.

Electrocardiography↗
PubMed1987

Regional left ventricular wall thickening by magnetic resonance imaging: evaluation in normal persons and patients with global and regional dysfunction.

Gated magnetic resonance imaging (MRI) provides excellent anatomic evaluation of the heart, but its capability for assessing cardiac physiology is less clear. Accordingly, regional left ventricular (LV) wall thickening was evaluated by multiphasic transverse images in 37 patients with a variety of myocardial diseases and in 9 normal subjects. Angiography and 2-dimensional echocardiography (2-D echo) were used for comparison. End-diastolic and end-systolic wall thickness, absolute systolic wall thickening and percent systolic wall thickening were determined in 7 regions. Mean systolic wall thickening in normal subjects was not significantly different among the regions. However, there was considerable individual variation in wall thickening, ranging from 18 to 100%. Patients with LV hypertrophy (n = 4), amyloid cardiomyopathy (n = 1), constrictive pericarditis (n = 5), and hypertrophic cardiomyopathy (n = 3) had absolute and percent systolic wall thickening within normal limits. Infarcted segments in patients with ischemic heart disease (n = 17) had reduced absolute and percent systolic wall thickening, often combined with diastolic wall thinning, whereas mean percent systolic wall thickening in adjacent normal myocardial regions was higher than in normal volunteers (p less than 0.001). In patients with coronary artery disease, MRI had a sensitivity and specificity of 93% in detecting regional wall motion abnormalities. Because sagittal images were not acquired, inferior wall motion abnormalities were not assessed by MRI due to parallel wall sectioning in transverse images.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomegaly↗