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Biomedical subjects

P C Come

Publications and source records attributed to P C Come.

At least 19 recordsLinked to original sources
PubMed1998

Progressive enlargement of the regurgitant orifice in patients with chronic aortic regurgitation.

The severity of aortic regurgitation is dependent on the size of the regurgitant orifice, the left ventricular response to volume overload, and the diastolic pressure difference across the aortic valve. The purpose of this study was to test the hypothesis that the aortic regurgitant orifice increases over time in patients with audible chronic aortic regurgitation. To assess serial changes in aortic regurgitant severity by the use of two-dimensional and Doppler echocardiography, 59 patients (29 men and 30 women) with audible chronic aortic regurgitation were prospectively identified and evaluated annually with two-dimensional and Doppler echocardiograms. Patients were followed for a median of 38 months. We measured two separate indicators of the size of the regurgitant orifice: the color Doppler regurgitant jet width and the Doppler-derived regurgitant orifice area. Jet width increased with time (0.5 +/- 0.4 cm at baseline, 0.04 +/- 0.01 cm/year slope, p < 0.001). The regurgitant orifice area also increased (0.12 +/- 0.14 cm2 at baseline, 0.01 +/- 0.01 cm2/year, p = 0.05). Changes in regurgitant orifice area were related to changes in left ventricular end-diastolic dimension (p < 0.001). There were no significant changes in left ventricular chamber dimensions, volumes, and regurgitant volume over time in this cohort. Increases in jet width and orifice area occurred in patients with all degrees of baseline disease severity, with bicuspid or tricuspid leaflet morphology, and with male or female sex. In this prospective study of chronic aortic regurgitation, both jet width and Doppler-derived regurgitant orifice area increased over time. These findings suggest that one factor in the progression of chronic aortic regurgitation is enlargement of the orifice.

Aortic Valve↗
PubMed1997

Impact of valvular regurgitation and ventricular dysfunction on long-term survival in patients with chest pain.

Doppler echocardiography is often used in evaluating patients with chest pain, but information on prognostic value of this testing and data to help guide selective use are limited. We prospectively studied 448 patients admitted from the emergency department for acute chest pain to assess the utility of qualitative echocardiographic data in predicting long-term survival and the incremental value of this information over routine clinical and electrocardiographic data. Doppler echocardiograms, recorded an average of 21 hours after presentation, were analyzed independently by 2 echocardiographers for global left and right ventricular function and valvular disease. Regional function was assessed by wall motion index. Data on long-term survival were collected with an average follow-up of 35.0 +/- 12.1 months. In univariate Cox regression analysis, left ventricular function and size, wall motion index, right ventricular function, and aortic, mitral, and tricuspid insufficiency were significant predictors of total and cardiovascular mortality. In multivariate analysis, moderate or severe left ventricular dysfunction (mortality rate ratio 3.2, 95% confidence intervals 1.8 to 5.8] and more than mild valvular regurgitation (mortality rate ratio 2.0, 95% confidence interval 1.1 to 3.6) were independent predictors of mortality in a model adjusted for clinical and electrocardiographic data. These factors were more common in patients aged >60 years, in those with prior acute myocardial infarction or angina, and in those with rales on physical examination. In the absence of these clinical characteristics, only 8 of 124 patients (7%) had moderate or severe left ventricular dysfunction or valvular regurgitation. In patients with moderate or severe regurgitation, a murmur was noted on the admission physical examination in 41 of 69 cases (59%). We conclude that echocardiographic evidence of moderate or severe left ventricular dysfunction or valvular regurgitation identifies a high-risk group for overall and cardiovascular mortality in patients with chest pain, and this evidence may not be detected clinically.

Adult↗
PubMed1997

Echocardiographic prediction of complications in patients with chest pain.

The optimal role of Doppler echocardiography in the evaluation of patients with acute chest pain syndromes is unclear. We prospectively studied a cohort of 466 patients admitted with acute chest pain syndromes to clarify the relation between echocardiographic data and the risk of serious predischarge complications, and to determine if echocardiographic data can provide incremental prognostic information beyond clinical and electrocardiographic variables. Doppler echocardiograms, performed an average of 21 hours after presentation, were independently analyzed by 2 echocardiographers for information on global left and right ventricular function and valvular disease. Regional function was assessed by a wall motion index (WMI). A composite complications end point was positive if significant recurrent myocardial ischemia, heart failure, or arrhythmia developed after the echocardiogram. In univariate analysis, left (odds ratio [OR] 2.9, 95% confidence interval [CI] 1.6, 5.1) and right (OR 2.7, 95% CI 1.2, 6.2) ventricular function, left ventricular end-diastolic (OR 1.6/cm, 95% CI 1.1, 2.3) and end-systolic (OR 1.4/cm, 95% CI 1.1, 1.9) dimensions, and WMI (OR 3.0, 95% CI 1.8, 4.8) predicted complications that developed after the echocardiogram. In multivariate analysis, WMI remained an incremental predictor of risk with an OR of 2.2/unit (95% CI 1.2, 3.9) scaled from 1 to 4. Even in the subset of 403 patients without acute myocardial infarction, WMI was associated with an OR of 1.9 (95% CI 1.0, 3.7). We conclude that early echocardiography provides incremental prognostic information concerning risk of subsequent complications in patients hospitalized with chest pain.

Adult↗
PubMed1997

Clinical and echocardiographic correlates of health status in patients with acute chest pain.

OBJECTIVE: To assess the ability of echocardiographic data to predict important functional status outcomes in patients with chest pain. DESIGN: Prospective cohort study. SETTING: A large, urban teaching hospital. PATIENTS: Three hundred thirty-three patients admitted from the Emergency Department for evaluation of chest pain. MEASUREMENTS AND MAIN RESULTS: Patients underwent two-dimensional and Doppler echocardiography as well as a face-to-face interview during their initial hospitalization and a telephone interview 1 year thereafter. The interview included the Medical Outcomes Study 36-Item Short Form (SF-36) health inventory, a generic health status instrument with a physical function subscale. The relation between clinical and echocardiographic factors and functional status was explored by univariable and multivariable linear regression and logistic regression analyses. Multiple clinical and echocardiographic factors correlated significantly with functional status measures at 1 year. For the SF-36 score at 1 year, age, male gender, white race, the presence of rales, and a comorbidity score were independently predictors in multivariate analysis; echocardiographic findings of severe left ventricular dysfunction (parameter estimate [PE] -27.6; 95% confidence interval [CI] -43.1, -12.2) and aortic insufficiency (PE -16.7; 95% CI -26.4, -7.0) added independent predictive information. Explanatory power (r2) for models using clinical and demographic variables was .27 and increased after inclusion of echocardiographic data to an r2 of .35. Results in the subset of patients (n = 148) with acute coronary syndromes such as unstable angina or myocardial infarction were qualitatively similar. Selected factors (rales on examination, electrocardiographic changes suggestive of ischemia, and moderate to severe mitral regurgitation) also predicted which patients would die or have a decline in their functional status. In multivariate analysis, only rales remained an independent predictor of poor outcome (odds ratio 2.4; 95% CI 1.2, 4.5). CONCLUSIONS: Echocardiographic data are correlated with measures of functional status in patients with chest pain, but the ability to predict future functional status from clinical or echocardiographic information is limited. Because functional status cannot be predicted adequately from either patients' characteristics or echocardiographic testing, it must be assessed directly.

Aged↗
PubMed1996

Regional right ventricular dysfunction detected by echocardiography in acute pulmonary embolism.

This study analyzed the regional pattern of right ventricular (RV) dysfunction on transthoracic echocardiograms in patients with and without acute pulmonary embolism. Quantitative (centerline) and qualitative (wall motion score) analyses of segmental RV free wall motion were performed on a "training" cohort of 41 patients (group 1), including 14 patients with acute pulmonary embolism, 9 patients with primary pulmonary hypertension, and 18 normal subjects. Patients with acute pulmonary embolism had a distinct regional pattern of RV dysfunction, with akinesia of the mid-free wall (centerline excursion: -0.2 +/- 0.8 mm, p = 0.0001 vs normal) but normal motion at the apex (centerline excursion: 5.7 +/- 0.8 mm, p = NS vs normal). In contrast, patients with primary pulmonary hypertension had abnormal wall motion in all regions (p <0.03 vs normal). This echocardiographic finding of normal wall motion at the apex and abnormal wall motion in the mid-free wall in acute pulmonary embolism was then tested in a "validation" cohort of 85 patients (group 2), consisting of hospitalized patients with RV dysfunction from any cause, including 13 patients with acute pulmonary embolism. The finding had a 77% sensitivity and a 94% specificity for the diagnosis of acute pulmonary embolism, with a positive predictive value of 71% and a negative predictive value of 96%. Thus, a distinct echocardiographic pattern of regional RV dysfunction, in which the apex is spared occurs in acute pulmonary embolism. This finding should raise the level of clinical suspicion for the diagnosis of acute pulmonary embolism.

Acute Disease↗
PubMed1994

Prognostic significance of right ventricular hypokinesis and perfusion lung scan defects in pulmonary embolism.

We studied the relation between right ventricular (RV) hypokinesis on echocardiography and defects on the initial perfusion lung scan among 90 hemodynamically stable patients with pulmonary embolism (PE). Of the 90, 38 had qualitative evidence of RV hypokinesis, with a mean RV end-diastolic area significantly larger than those with normal RV wall motion (40.0 +/- 10.2 cm2 vs 20.1 +/- 6.4 cm2; p < 0.001). The degree of the perfusion defect was greater in those patients with baseline RV hypokinesis (54% +/- 16% of the lung nonperfused) than in those patients with normal RV wall motion at baseline (30% +/- 18% nonperfused lung; p < 0.001). Receiver operating characteristic curve analysis showed that a perfusion lung scan defect score of 0.3 (i.e., 30% of the lung nonperfused) had a 92% sensitivity for predicting RV hypokinesis and carried a relative risk for observing RV hypokinesis of 6.8 times greater than among those patients with a perfusion scan score of < 0.3. Considering that all patients with recurrent symptomatic PE were in the subgroup with RV hypokinesis (13% vs 0% for those with normal RV wall motion; p = 0.01), a strategy of performing echocardiography in those patients with a perfusion scan defect score of > or = 0.3 appears to identify patients at increased risk for recurrent PE.

Chi-Square Distribution↗
PubMed1994

Impaired left atrial mechanical function after cardioversion: relation to the duration of atrial fibrillation.

OBJECTIVES: We hypothesized that the time course of the recovery of atrial systolic function may be related to the duration of atrial fibrillation before cardioversion and sought to study noninvasively the recovery of left atrial mechanical function utilizing serial transthoracic Doppler studies. BACKGROUND: Recovery of atrial mechanical function may be delayed for several weeks after successful cardioversion of atrial fibrillation to sinus rhythm. METHODS: After successful cardioversion, 60 patients with atrial fibrillation of brief (< or = 2 weeks, 17 patients), moderate (> 2 to 6 weeks, 22 patients) or prolonged (> 6 weeks, 21 patients) duration were followed up with serial transmitral pulsed Doppler echocardiography immediately (60 patients) and at 24 h (45 patients), 1 week (41 patients), 1 month (31 patients) and > 3 months (30 patients) after cardioversion. RESULTS: Atrial mechanical function is greater immediately and at 24 h and 1 week after cardioversion in patients with "brief" compared with "prolonged" atrial fibrillation. In all groups, atrial mechanical function increases over time, ultimately achieving similar levels. Full recovery of atrial mechanical function, however, is achieved within 24 h in patients with brief atrial fibrillation, within 1 week in patients with moderate-duration atrial fibrillation and within 1 month in patients with prolonged atrial fibrillation. CONCLUSIONS: Recovery of left atrial mechanical function is related to the duration of atrial fibrillation before cardioversion. These findings have important implications for assessing the early hemodynamic benefit of successful cardioversion.

Adult↗
PubMed1993

Alteplase versus heparin in acute pulmonary embolism: randomised trial assessing right-ventricular function and pulmonary perfusion.

Data from a non-randomised study have hinted that in patients with acute pulmonary embolism (PE), thrombolysis followed by heparin more rapidly reverses right-ventricular dysfunction and restores pulmonary tissue perfusion than does heparin alone. We have pursued this idea in a randomised protocol. 46 haemodynamically stable patients were randomised to recombinant tissue plasminogen activator (alteplase, rt-PA) 100 mg over 2 h followed by intravenous heparin and 55 to heparin alone. Right-ventricular wall motion was assessed qualitatively, and right-ventricular end diastolic area was estimated by planimetry from echocardiograms at baseline and at 3 and 24 hours. Pulmonary perfusion scans were obtained at baseline and 24 hours. In 39% of rt-PA patients but in only 17% of heparin alone patients right-ventricular wall motion at 24 hours had improved from baseline and in 2% and 17%, respectively, it worsened (p = 0.005). rt-PA patients also had a significant decrease in right-ventricular end-diastolic area during the 24 hours after randomisation and a significant absolute improvement in pulmonary perfusion (14.6% vs 1.5%). No clinical episodes of recurrent PE were noted among rt-PA patients, but there were 2 fatal and 3 non-fatal clinically suspected recurrent PEs within 14 days in patients randomised to heparin alone. rt-PA rapidly improves right-ventricular function and pulmonary perfusion among patients with PE and may lead to a lower rate of adverse clinical outcomes.

Acute Disease↗
PubMed1992

An experimental model of acute and subacute viral myocarditis in the pig.

Twenty-six young pigs were infected with encephalomyocarditis virus, observed clinically, studied at intervals by noninvasive and invasive methods to assess cardiac function and eventually examined pathologically. All infected animals appeared ill, usually manifesting diminished appetite, lethargy and fever. Spontaneous mortality occurred either 1 to 4 or 20 to 21 days after infection. Electrocardiographic abnormalities, seen in the majority of animals, comprised ST-T wave changes, conduction disturbances or ventricular ectopic rhythm. The majority of animals manifested echocardiographic evidence of left ventricular dilation and decreased systolic function, which improved with time in some animals. Hemodynamic studies revealed elevation of biventricular filling pressures in 3 of 10 animals; as a group, infected animals manifested significantly elevated right ventricular filling pressures. In selected animals, the feasibility of gallium scans as well as left ventriculography and coronary angiography was demonstrated. At autopsy, heart weight/body weight ratio was significantly elevated in infected animals. The heart of all but two animals showed active myocarditis associated with fibrosis and focal calcification in the later stages. In general, the cardiovascular manifestations were parallel with those seen in acute and subacute myocarditis in humans. It is concluded that encephalomyocarditis infection in the pig is a large animal model of viral myocarditis suitable for assessing alterations in the structure and function of the cardiovascular system and the effects of interventions.

Animals↗
PubMed1992

Two-dimensional and Doppler echocardiographic determinants of the natural history of mitral valve narrowing in patients with rheumatic mitral stenosis: implications for follow-up.

Fifty patients with rheumatic mitral stenosis were studied with serial two-dimensional and Doppler echocardiography to determine the natural history of changes in mitral valve area and its relation to transmitral gradients and mitral valve morphology. Over the 39-month observation period (range 7 to 74 months) the decline in valve area was 0.09 +/- 0.21 cm2/year. In addition, there were significant increases in total echocardiographic score (p = 0.0001), severity of mitral anulus calcification (p = 0.05) and severity of mitral regurgitation (p = 0.0007). Patients with an echocardiographic score greater than or equal to 8 had a more progressive course. In addition, patients with a more progressive course (decline in valve area greater than or equal to 0.1 cm2/year) had a significantly greater initial mean gradient (p = 0.01), peak gradient (p = 0.007) and total echocardiographic score (p = 0.0008). Initial valve area did not correlate with the rate of stenosis progression. Of 22 patients with an echocardiographic score less than 8 and a peak mitral gradient less than 10 mm Hg, only 1 patient (5%) had a more progressive course, compared with 80% of those with a total echocardiographic score greater than or equal to 8 and a gradient greater than or equal to 10 mm Hg. The rate of mitral valve narrowing in individual patients with rheumatic mitral stenosis is variable. Patients whose valve disease progresses rapidly are those with a greater mitral valve echocardiographic score and higher peak and mean transmitral gradients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Echocardiographic evaluation of pulmonary embolism and its response to therapeutic interventions.

Imaging and Doppler echocardiography permits assessment of right ventricular size and systolic function and of pulmonary arterial pressures, and it may facilitate detection of thromboemboli within the heart or pulmonary artery. In patients with acute pulmonary embolism of sufficient severity to appreciably increase right ventricular afterload, the right ventricle becomes dilated and hypokinetic. Tricuspid regurgitation is generally apparent, but in the absence of preexisting pulmonary arterial or left heart pathology, the regurgitant flow velocity suggests only mild to mild-moderate elevation of pulmonary arterial systolic pressure. The absence of a greater degree of pulmonary hypertension reflects the inability of the previously normal, nonhypertrophied right ventricle to generate a mean pulmonary arterial pressure in excess of about 40 mm Hg. The echocardiographic abnormalities resolve during recovery from pulmonary embolism. Currently being investigated is the question of whether right heart abnormalities resolve more rapidly with thrombolytic therapy than with heparin therapy alone.

Diagnosis, Differential↗
PubMed1991

Implications of echocardiographically assisted diagnosis of pericardial tamponade in contemporary medical patients: detection before hemodynamic embarrassment.

Identification of suspected pericardial tamponade and the decision to perform invasive drainage of the pericardial space have historically been based on classic bedside findings. Two-dimensional echocardiography has improved detection of pericardial effusion, but it may be excessively sensitive in evaluation of patients for hemodynamic embarrassment. Therefore, 50 consecutive medical patients were examined who were identified by echocardiography to have probable tamponade (defined as the presence of right heart chamber collapse in the presence of a pericardial effusion) and who underwent combined right-sided cardiac catheterization and percutaneous pericardiocentesis. All patients had elevated pericardial pressure. However, many had minimal evidence of hemodynamic compromise (94% had systolic blood pressure greater than or equal to 100 mm Hg and 58% had a cardiac index greater than or equal to 2.3 liters/min per m2). Pericardiocentesis resulted in hemodynamic improvement, but frequently did not alleviate dyspnea or correct tachycardia. Patients with malignancy as the cause of tamponade had a high mortality rate (the cumulative probability of survival in such patients was only 17% at 1 year). Echocardiographically assisted diagnosis of pericardial tamponade in medical patients results in the identification of a substantial subset of patients with only subtle evidence of hemodynamic compromise. This subset of patients differs sharply from medical patients described in previous reports with classic tamponade. Although the patients can be managed by invasive catheter pericardiocentesis with few complications, the natural history and the optimal management strategy for this group are not resolved.

Cardiac Catheterization↗
PubMed1989

The effect of caffeine on exercise tolerance and left ventricular function in patients with coronary artery disease.

STUDY OBJECTIVE: To determine whether acute oral caffeine ingestion by patients with coronary artery disease results in decreased treadmill exercise performance or deterioration of echocardiographic measures of systolic or diastolic left ventricular function. DESIGN: Randomized, double-blind, placebo-controlled trial. SETTING: Referral-based cardiovascular exercise laboratory at an urban teaching hospital. PATIENTS: Thirteen volunteers with clinically stable coronary artery disease who had exercise tests after a 2-week caffeine-free washout period. Patients continued treatment with standard antianginal medications during the study period. INTERVENTIONS: Maximal exercise treadmill testing and exercise echocardiography were done at baseline, after acute ingestion of a placebo beverage (97% caffeine-free coffee), or after drinking an identical beverage containing 250 mg of caffeine sodium benzoate. MEASUREMENTS AND MAIN RESULTS: Acute ingestion of caffeine produced a serum level of 4.50 +/- 0.16 micrograms/mL, but had no effect on resting supine heart rate, blood pressure, left ventricular fractional shortening, posterior left ventricular wall thinning or peak rates of increase in left ventricular diastolic dimension. Despite a small increase in peak systolic blood pressure during exercise (baseline, 153 +/- 8; placebo, 154 +/- 8; caffeine, 161 +/- 7 mm Hg; P less than 0.05), exercise duration, time to onset of angina, and time to 0.1 mV ST depression did not differ after ingestion of placebo or caffeine. Rate-pressure product at onset of angina and onset of 0.1 mV of ST depression were also unchanged. In response to exercise, echocardiographic measures of left ventricular systolic and diastolic function were unchanged after caffeine compared with placebo ingestion. CONCLUSIONS: These data suggest that patients with exercise-induced ischemia who are receiving appropriate antianginal therapy tolerate the caffeine-equivalent of three cups of coffee without detrimental effect on intensity of ischemia, myocardial function, or exercise duration.

Adult↗
PubMed1989

Pulsed Doppler evaluation of atrial mechanical function after electrical cardioversion of atrial fibrillation.

Full recovery of atrial mechanical activity may not occur immediately after successful electrical cardioversion of atrial fibrillation to sinus rhythm. To examine the time course of recovery of left atrial mechanical function, serial two-dimensional, M-mode and transmitral pulsed Doppler echocardiographic studies were performed in 21 patients after elective direct current cardioversion of atrial fibrillation of 3 weeks' to 24 months' duration (mean 5 months). Over 3 months of follow-up, there were significant increases in both peak A wave velocity (p less than 0.005) and percent atrial contribution to total left ventricular filling (p less than 0.005). Compared with values in a normal control population, peak A wave velocity and percent atrial contribution to total left ventricular filling did not return to normal until 3 weeks after cardioversion in patients who remained in sinus rhythm. Left atrial dimension also decreased over the follow-up period (p less than 0.05) in patients with persistent sinus rhythm. These results may have important implications in guiding the appropriate duration of anticoagulant therapy after cardioversion, and in clinically assessing the hemodynamic benefit of restoring sinus rhythm in an individual patient.

Aged↗
PubMed1989

Pulsed Doppler echocardiographic determination of the time course of left ventricular filling: validation with cineangiography.

Several noninvasive techniques are used to evaluate left ventricular diastolic function, but none has optimally characterized the time course of left ventricular filling. We have developed a method to characterize left ventricular filling, by integrating Doppler measurements of flow velocity across the mitral valve. The purpose of the present study was to compare this new method with contrast left ventriculographic assessment of left ventricular filling. Pulsed Doppler studies were obtained within 24 hours of left ventriculography in 15 patients: three normal subjects, seven with coronary disease, two with mitral stenosis, and three with dilated cardiomyopathy. Patients with myocardial infarction, regional wall movement abnormalities, or aortic regurgitation were excluded. Doppler-derived relative left ventricular filling was compared to filling from right anterior oblique left ventriculograms. Doppler and angiographic filling curves were qualitatively different in normal subjects and in patients with mitral stenosis and cardiomyopathy. For individual patients, however, the Doppler and angiographic filling curves were qualitatively similar, with a strong correlation between Doppler and angiographic estimates of percent filling (r = 0.95; p less than 0.001). These preliminary observations suggest that Doppler echocardiography may provide a reliable assessment of the time course of left ventricular diastolic filling. Further studies are warranted and should include more patients with diverse cardiac abnormalities.

Adult↗
PubMed1989

Serial assessment of mitral regurgitation by pulsed Doppler echocardiography in patients undergoing balloon aortic valvuloplasty.

Mitral regurgitation was serially assessed by pulsed Doppler echocardiography in 144 patients undergoing balloon aortic valvuloplasty for symptomatic aortic stenosis. Regurgitant scores of 0, 1, 2 and 3 were assigned to pulsed Doppler patterns corresponding to no, mild, moderate and severe mitral regurgitation, respectively. Before balloon aortic valvuloplasty, mitral regurgitant score correlated significantly (p less than 0.005) but weakly with aortic valve area (r = -0.24), left ventricular ejection fraction (r = -0.34) and left ventricular systolic pressure (r = 0.23). There was no significant correlation between mitral regurgitation and either mean catheterization or mean Doppler aortic valve gradient. Balloon aortic valvuloplasty produced significant decreases in both catheterization and Doppler mean transvalvular aortic valve gradients (56 +/- 19 to 31 +/- 12 and 60 +/- 19 to 48 +/- 16 mm Hg, respectively; both p less than 0.0001) and a significant increase (p less than 0.0001) in aortic valve area assessed by catheterization (0.6 +/- 0.2 to 0.9 +/- 0.3 cm2). Left ventricular ejection fraction did not change, but cardiac output increased (p less than 0.001) and pulmonary capillary wedge pressure decreased (p less than 0.0001). Pulsed Doppler findings of mitral regurgitation were present in 102 of the 144 patients. Eighty-eight patients had a score compatible with mild or more severe degrees of mitral regurgitation, and 49 had a score indicative of moderate or severe valvular insufficiency. In the entire group of 144 patients, mitral regurgitant score decreased significantly from 1.1 +/- 1.0 to 1.0 +/- 1.0 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗