Frequency of late potentials in systemic sclerosis.
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Biomedical subjects
Publications and source records attributed to J S Child.
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Afterload reduction therapy can acutely improve hemodynamic function in patients with advanced heart failure; however, it is unknown if initial reductions in mitral and tricuspid regurgitation and atrial volumes can be sustained with oral therapy. Atrial volumes and atrioventricular valve regurgitation were measured using 2-dimensional and Doppler echocardiography with color-flow imaging in 14 patients with dilated heart failure (ejection fraction 17 +/- 4%) before and after 3 +/- 1 days of intensive vasodilator and diuretic therapy tailored to hemodynamic goals. Echocardiography was repeated again after 6 +/- 2 months on oral vasodilators and a flexible diuretic regimen. Acute therapy reduced systemic vascular resistance from 1,760 +/- 460 to 1,010 +/- 310 dynes.s.cm-5, pulmonary artery wedge pressure from 30 +/- 5 to 17 +/- 4 mm Hg, and right atrial pressure from 13 +/- 5 to 7 +/- 3 mm Hg, and led to a 61% increase in stroke volume (from 36 +/- 10 to 58 +/- 14 ml) (p less than 0.01). Mitral and tricuspid regurgitation, determined by color-flow fraction, initially decreased from 0.34 +/- 0.17 to 0.20 +/- 0.20 and from 0.33 +/- 0.15 to 0.13 +/- 0.13, respectively (p less than 0.001). This reduction was sustained at 6 months. Significant decreases occurred with acute therapy, with further reductions at 6 months in both mean left atrial volume (from 100 +/- 25 to 80 +/- 19 to 65 +/- 15 cm3) and right atrial volume (from 85 +/- 23 to 64 +/- 23 to 52 +/- 14 cm3) (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)
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Although revascularization of hypoperfused but metabolically active human myocardium improves segmental function, the temporal relations among restoration of blood flow, normalization of tissue metabolism and recovery of segmental function have not been determined. To examine the effects of coronary angioplasty on 13 asynergic vascular territories in 12 patients, positron emission tomography and two-dimensional echocardiography were performed before and within 72 h of revascularization. Ten patients underwent late echocardiography (67 +/- 19 days) and eight underwent a late positron emission tomographic study (68 +/- 19 days). The extent and severity of abnormalities of wall motion, perfusion and glucose metabolism were expressed as wall motion scores, perfusion defect scores and perfusion-metabolism mismatch scores. Angioplasty significantly increased mean stenosis cross-sectional area (from 0.95 +/- 0.9 to 2.7 +/- 1.4 mm2) and mean cross-sectional luminal diameter (from 0.9 +/- 0.6 to 1.9 +/- 0.5 mm) (both p less than 0.001). Perfusion defect scores in dependent vascular territories improved early after angioplasty (from 116 +/- 166 to 31 +/- 51, p less than 0.002) with no further improvement on the late follow-up study. The mean perfusion-metabolism mismatch score decreased from 159 +/- 175 to 65 +/- 117 early after angioplasty (p less than 0.01) and to 26 +/- 29 at late follow-up (p less than 0.001 vs. before angioplasty; p = NS vs. early after angioplasty). However, absolute rates of glucose utilization remained elevated early after revascularization, normalizing only at late follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)
Myocardial ischemia causes regional myocardial contractile and relaxation abnormalities. The extent of ischemia is determined by the distribution and severity of coronary artery stenoses. In coronary heart disease, two powerful predictors of prognosis are the coronary anatomy and ventricular function. Management in coronary heart disease is directed by accurate diagnosis and individualized objectives. Echocardiography at rest and exercise, combined with Doppler and color flow imaging, are properly applied to the differential diagnosis of common clinical syndromes in ischemic heart disease, the identification of the proximal coronary arteries, and the effects of ischemia and prior infarction. Subsequent use of coronary arteriography partially depends on the philosophy regarding the applicability of coronary surgery or angioplasty in an individual patient. Prediction of multivessel, left main, or proximal left anterior descending coronary artery disease by extensive wall motion abnormalities or an abnormal left ventricular ejection fraction may direct the clinician to coronary arteriography to select among coronary surgery, angioplasty, or medical management.
Recent laboratory investigations have shown significantly improved donor heart preservation and function when the University of Wisconsin solution (UW) is used for arrest and storage. These findings prompted us to compare UW to Stanford solution in a clinical trial. After giving informed consent, patients were blindly randomized to receive a heart arrested and stored in UW or a heart arrested in Stanford solution and stored in normal saline. Orthotopic transplants were performed in a routine manner. Fourteen patients with a mean age of 54 years were randomized to UW, and 15 patients with a mean age of 51 years were randomized to Stanford solution. Mean donor ages (UW 27 years, Stanford 24 years) and ischemic times (UW 150 minutes, Stanford 135 minutes) were similar. Several differences were observed intraoperatively. At end ischemia, mean adenosine triphosphate (UW 5.87 mmol/gm wet weight, Stanford 4.75 mmol/gm) and creatine phosphate (UW 9.26 mmol/gm, Stanford 4.75 mmol/gm) levels were higher in the UW hearts (p less than 0.05). Defibrillation requirements (UW 14% [2/14], Stanford 53% [8/15]) were significantly less in the UW group (p = 0.05). The number of patients requiring temporary intraoperative pacing also showed a significant difference with 7% (1/14) of UW patients versus 47% (7/15) of Stanford patients requiring pacing (p less than 0.05). Intraoperative requirement for inotropic support showed a trend in favor of the UW group. End-ischemic and postreperfusion histologic characteristics were similar between the two groups. No differences in hemodynamics or ejection fractions were noted postoperatively, but trends toward improved rhythm and decreased inotropic support were present in the UW group. Overall 6-month survival rates were similar (UW 86% [12/14], Stanford 93% [14/15]). No preservation-related deaths occurred. We conclude: (1) UW is a safe and effective preservation solution for human cardiac transplantation; (2) considering the improved end-ischemic adenosine triphosphate and creatine phosphate levels, decreased defibrillations, decreased intraoperative pacing, and trend toward decreased requirement for inotropic support in the UW group, UW appears to be superior to Stanford solution for donor heart preservation.
Although acute afterload reduction is known to improve cardiac output in patients with congestive heart failure (CHF), the effect of therapy on the atrial overload directly causing congestive symptoms has not been systematically studied. Atrial volumes and mitral and tricuspid regurgitation, in addition to left ventricular ejection fraction and indexes of left ventricular contractility (mean acceleration, ejection time and peak systolic pressure/end-systolic volume index), were measured using 2-dimensional and Doppler echocardiography and color flow imaging in 30 patients with advanced CHF, before and after acute vasodilator and diuretic therapy tailored to hemodynamic goals. Therapy increased stroke volume by 64% (36 +/- 10 to 55 +/- 14 cc), decreased right atrial pressure by 45% (15 +/- 5 to 8 +/- 4 mm Hg), systemic vascular resistance by 36% (1,700 +/- 400 to 1,030 +/- 300 dynes s cm-5) and pulmonary capillary wedge pressure by 37% (31 +/- 6 to 19 +/- 6 mm Hg) (all p less than 0.001). Echocardiography showed simultaneous reductions in left and right atrial volumes: 24 +/- 19 and 18 +/- 12%, respectively (p less than 0.001). Mitral and tricuspid regurgitation measured by color flow fraction both decreased by a mean of 44% (p less than 0.001). While ejection fraction increased from 15 +/- 5 to 19 +/- 7% (p less than 0.001), there were no changes in relatively load-independent indexes of contractility. Therefore, acute therapy with vasodilators and diuretics in advanced CHF causes reductions in atrial volumes and atrioventricular valve regurgitation that are evident from serial noninvasive studies and may play a major role in the improvement of congestive symptoms.
Enormous strides in diagnosis and management have allowed many patients with congenital heart disease to reach adulthood. Proper care of these individuals requires knowledge of the anatomic and hemodynamic faults of the original defect, the dynamic changes that occur with time, and the effects of adult diseases or surgical intervention on that physiology. Echocardiographic and Doppler assessment of these patients has revolutionized their management. This article has discussed individual abnormalities such as shunts, obstructive or regurgitant lesions, and great-vessel and chamber malpositions, as well as selective aspects of more complex malformations. In the patient with congenital heart disease, whether unoperated or postoperative, a complete echo-Doppler examination includes complete anatomic delineation of intra- and extracardiac structures using combined two-dimensional and color-flow imaging, assessment of chamber sizes and myocardial function, and complementary pulsed and continuous-wave Doppler and color-flow imaging to search for and quantitate valvular, subvalvular or supravalvular stenosis or regurgitation; extra- and intracardiac conduit stenosis; pulmonary and systemic venous obstruction; transseptal or patch shunts; and intracardiac hemodynamics.
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Hematologic management of adults with cyanotic congenital heart disease has received little recent attention. The lack of practical therapeutic guidelines prompted us to consolidate our observations on 124 cyanotic adults for general physicians, cardiologists, and hematologists who care for these patients. Specific attention focused on regulation of erythrocyte mass and concepts of compensated and decompensated erythrocytosis, symptoms of deficient tissue oxygen transport, hyperviscosity and iron deficiency, the potential relation between elevated hematocrit levels and brain injury, hemostasis, urate metabolism, and renal function. Cerebral infarction was not seen in any patient. Phlebotomy is best reserved for treatment of symptomatic hyperviscosity. Iron therapy is indicated for symptomatic iron deficient erythropoiesis. Abnormal hemostatic mechanisms are the rule. Antithrombotic medications have little or no role in treatment. Hyperuricemia is the result of abnormal renal uric acid excretion not urate overproduction, and serves as a marker of abnormal renal function. Drugs that promote urate excretion are the preferred maintenance treatment in symptomatic hyperuricemic patients.
Exercise-induced myocardial ischemia results in both diastolic and systolic left ventricular (LV) dysfunction. To investigate the utility of Doppler assessment of LV diastolic function with exercise, 28 consecutive patients underwent digital stress echocardiography, including measurement of mitral flow velocity by pulsed-wave Doppler and simultaneous stress thallium imaging. The mean mitral flow velocity was measured as the integrated area under the LV diastolic inflow Doppler spectral display. The change in mean mitral flow velocity from baseline to immediate postexercise was compared among 3 patient groups: (1) patients with thallium redistribution or exercise-induced wall-motion abnormalities, or both, consistent with exercise-induced ischemia (n = 18), (2) patients with no evidence of stress-induced ischemia, with or without resting wall-motion abnormalities (n = 10), and (3) 10 control subjects of similar age with normal resting 12-lead electrocardiograms, normal resting and postexercise 2-dimensional echocardiograms and normal electrocardiographic treadmill stress testing. The percent increase in mean mitral flow velocity was 101% (+/- 59) for controls and 86% (+/- 53) for patients without stress-induced ischemia versus 33% (+/- 24) in patients with stress-induced ischemia (p less than 0.005). An increase in mean mitral flow velocity with exercise of greater than 50% correctly identified 9 of 10 nonischemic control patients. An increase in mean velocity of less than 50% predicted ischemia in 15 of 18 patients with evidence of stress-induced ischemia (p less than 0.005) Thus, Doppler assessment of LV diastolic function with exercise expressed as a change in the mean velocity of mitral flow is a useful indicator of stress-induced ischemia.
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Commonly used echocardiographic criteria for mitral valve prolapse (MVP) include a sizable proportion of persons whose hearts are normal. Nevertheless, the echocardiogram is generally used as an independent standard for the diagnosis of MVP despite lack of consensus on the criteria to be used and the probability of interobserver variability. Conversely, there is a relatively uniform consensus that classic auscultatory signs establish the diagnosis of MVP beyond reasonable doubt. Accordingly, in 148 patients referred for evaluation of known or suspected MVP, the echocardiographic patterns that coincide with diagnostic auscultatory signs were studied prospectively to compare those patterns with criteria commonly used for the echocardiographic diagnosis of MVP and to determine interobserver variability in echocardiographic interpretation. Eighty patients (54%) had a classic mid- to late systolic click or an apical late systolic murmur, or both. Eleven patients (7%) had the apical holosystolic murmur of mitral regurgitation with no discernible clinical or echocardiographic cause other than the consideration of MVP. Doppler echocardiography was performed in 80 of the 148 patients. The degree of superior systolic bowing of each mitral leaflet and the location of leaflet coaptation relative to the presumed plane of the mitral anulus were graded on apical 4-chamber and parasternal long-axis views. The only patterns absolutely specific for auscultatory MVP were: severe bowing of the anterior or posterior leaflet; coaptation of leaflets on the left atrial side of the anular plane; moderate to severe Doppler mitral regurgitation accompanied by any degree of leaflet bowing; and mild Doppler mitral regurgitation accompanied by moderate bowing of a leaflet.(ABSTRACT TRUNCATED AT 250 WORDS)
The physiologic role of the right ventricle has long been a subject of interest to physiologists. The Fontan operation provides a human model for studying the circulation in series devoid of a subpulmonic right ventricle. The hemodynamic response to isotonic exercise in this setting has been established, and differs appreciably from normal. However, the physiologic response to an increase in heart rate (atrial pacing) as an isolated variable has not been examined and compared to atrial pacing in hearts with two concordant subarterial ventricles. Accordingly, we compared the supine bicycle exercise response to rate-equivalent right atrial pacing in nine patients after atriopulmonary anastomoses (the Fontan operation) for single ventricle or tricuspid atresia. Cardiac index increased 77% with exercise (rest 2.6 L/min/m2; exercise 4.6 L/min/m2) but decreased 12% with atrial pacing (rest 2.5 L/min/m2; pacing 2.2 L/min/m2). Pulmonary arterial oxygen saturation declined significantly during exercise (rest 68%; exercise 31%) and during atrial pacing (control 72%; pacing 64%). The mean increment in pulmonary arterial pressure was 1.3 times greater with exercise (rest 14 mm Hg; exercise 20 mm Hg) than with pacing (control 12 mm Hg; pacing 16 mm Hg). Peak systemic arterial systolic pressure increased 14% with exercise but was unchanged by pacing. Systemic and pulmonary vascular resistances fell with exercise but changed insignificantly during atrial pacing. Stroke volume rose slightly with exercise but fell significantly with pacing.(ABSTRACT TRUNCATED AT 250 WORDS)
All victims of blunt injury to the chest or precordium admitted to a Level I trauma center in a 1-year period were evaluated prospectively with two-dimensional echocardiography on the day of admission, serial determinations of creatine kinase (CK) and MB isoenzyme radioimmunoassay (CK-MB) over the first 24 hours, continuous electrocardiographic monitoring over at least the first day, and serial 12-lead electrocardiography (ECG) over the first 3 days. The patients were divided into four groups based upon the results of echocardiography. Group A (n = 35) had normal ECHO and ECG; Group B (n = 16), normal ECHO and abnormal ECG; group C (n = 14), ECHO showing abnormal wall motion and/or pericardial fluid; group D (n = 8), ECHO showing a nontraumatic valvular or wall motion abnormality. Nineteen patients required an operation under general anesthesia. Group C patients had significantly higher CK, CK-MB, numbers of associated injuries, and Injury Severity Scores; seven required invasive hemodynamic monitoring. No cardiac morbidity of general anesthesia was seen. We conclude that echocardiography is an important tool for diagnosis and triage which may be used to stratify a homogeneous patient population into groups with acute, chronic, and no cardiac disease. Cardiac injury occurs in a setting of multisystem trauma. Patients with normal echocardiogram and ECG on admission do not require intensive care monitoring.