Cardiovascular and respiratory physiopathological aspects of hypokinesia

The many effects of hypokinesia on the human organism are described. The differences in normally mobile subjects and hypokinetic subjects as relates to heart rate, average humeral pressure, cardiac capacity, cardia index, systolic range, and large cycle resistances are discussed. It is concluded that further studies must be carried out in seven specific areas of cariocirculatory damage due to hypokinesia

Value of transesophageal dobutamine stress echocardiography in assessing coronary artery disease

The introduction of digital echocardiography has significantly enhanced our ability to select the best set of frames for analysis. However, despite the beneficial attributes of transthoracic dobutamine stress echocardiography, poor quality 2-dimensional images continue to be a significant limiting factor in patients with chest deformities, severe chronic obstructive lung disease, marked obesity, and previous chest surgery. Transesophageal echocardiography provides a new window to monitor left ventricular contractility without the interference of bone and air-filled structures of the thoracic cage. The transesophageal dobutamine stress test is a logical but poorly explored modality to image/stress the heart in certain patients with known or suspected myocardial ischemia. Overall sensitivity (< or = 85%) and specificity (< or = 95-100%) of transesophageal dobutamine stress echocardiography appear to be similar to that of previous transthoracic studies, although no direct comparison has been accomplished between transthoracic and transesophageal stress images. False negative transesophageal dobutamine stress echocardiography results have been described in patients with single-vessel disease in whom ischemic regions may not have been visualized throughout the entire study. False positive study results may be present in patients with hypertension and myocardial hypertrophy that may have signs and symptoms of myocardial ischemia in absence of obstructive disease of the epicardial coronary arteries, presumably related to either microvascular disease or impaired vasodilatory reserve. The proportion of patients with coronary artery disease who need a transesophageal examination for reliable assessment of echocardiographic response to stress varies depending on the operators' skills, the interpreters' experience, and the use of videotape or digitizing systems for image analysis. Although clinically useful in its present transthoracic and transesophageal form, a major limitation of dobutamine stress echocardiographic study is the subjective visual interpretation of endocardial motion and wall thickening, which is only semiquantitative. Color kinesis and tissue Doppler imaging (TDI) are 2 novel echocardiographic techniques that color code endocardial motion and myocardial velocity online and have the potential to objectively quantify regional left ventricular function. Quantitative standardization of transthoracic and transesophageal data interpretation, such as establishing endocardial motion by color kinesis or velocity thresholds by TDI for an abnormal segmental response to stress, has the potential to decrease interobserver variability and increase interinstitutional agreement

Assessment of regional left ventricular function during exercise test with pulsed tissue Doppler imaging

To investigate whether mitral annular velocity, measured by tissue Doppler imaging (TDI), is able to get a feasible quantitative evaluation of global and regional left-ventricular function during exercise test, 29 patients with previous uncomplicated myocardial infarction were studied by exercise echocardiography. All patients underwent coronary arteriography within 10 days of stress echocardiography. All of them were in sinus rhythm and had no right or left bundle branch block or significant mitral regurgitation as observed by left ventriculography. A total of 12 patients had anteroseptal and/or posteroseptal wall asynergies and left anterior descending involvement; 9 patients had lateral and/or posteroinferior asynergies and left circumflex coronary artery involvement; 8 patients had inferior and posteroseptal wall asynergies and right coronary artery involvement. Twelve subjects of same age and sex with normal cardiovascular findings were selected as a control group. TDI sample volumes were set on the mitral annuli corresponding to anteroseptal, posterior, posteroseptal, lateral, anterior, and inferior wall in 4-chamber, 2-chamber, and long-axis views. There was a significant correlation between the left-ventricular ejection fraction (0.41 +/- 0.8) and the means of the systolic (S) values (6.1 +/- 0.9 cm/sec, r = 0.83, p < 0.01). The mean S at the sites corresponding to the infarct regions (5.5 +/- 0.4 cm/sec) was significantly lower than the control group (11 +/- 0.8 cm/sec, p < 0.001). After stress, in patients with multivessel disease, S values corresponding to remote regions were significantly lower (p < 0.01) compared with control subjects. Thus, the parameters obtained from mitral annular velocities with pulsed TDI in patients with previous myocardial infarction reflect left ventricular asynergy corresponding to the infarct regions and reversible regional dysfunction after exercise

Usefulness of echocardiography in the prognostic evaluation of non-Q-wave myocardial infarction.

Patients with non-Q-wave myocardial infarction (MI) are a heterogeneous population with a wide range of coronary disease severity and extent of myocardial necrosis, showing, therefore, different electrocardiographic findings and different outcomes. To evaluate the role of echocardiography in the management of non-Q-wave MI patients, 192 consecutive patients without previous MI were studied (78 with ST segment elevation, 56 with ST depression and 58 without ST modifications). All patients underwent 2-dimensional echocardiography (16-segment model) within 24 hours of admission to the coronary care unit. Wall-motion abnormalities, wall-motion score index, ejection fraction, and end-diastolic and end-systolic volumes were evaluated. In 35 patients, death, reinfarction, recurrent angina, or severe heart failure occurred during the in-hospital phase, whereas the remaining 157 patients had a good outcome. Patients with a poor prognosis were older (68 +/- 6 vs 59 +/- 5 years, p 3 segments 0.28 and 0.86; wall-motion score index > 1.33 = 0.28 and 0.87; end-diastolic volume > 46 mL/m2 = 0.49 and 0.91; ST segment depression and wall-motion abnormalities in > 3 segments 0.60 and 0.88. These results underline the usefulness of echocardiography in the early risk stratification of non-Q-wave MI patients, together with electrocardiographic data. Patients with ST segment depression and more extensive wall-motion abnormalities are at higher risk and their management needs a more aggressive approach

Clinical application of exercise stress echocardiography: Supine bicycle or treadmill?

Although exercise stress echocardiography is currently used to evaluate coronary artery disease (CAD) patients, the best exercise methodology is still undefined. The objectives of the study were: (1) to compare supine bicycle stress echocardiography (SBSE) and treadmill in the evaluation of CAD; and (2) to define, in normal subjects, the different behavior of factors determining MVO2 wish treadmill and SBSE. We selected 10 male patients with CAD (group A), and 10 male control subjects (group B). Each patient underwent SBSE and tread-mill testing in random order. We studied heart sate, systolic blood pressure, heart rate x systolic blood pressure, and end-diastolic and end-systolic volume indexes. in group A, we also studied wall motion score index (according to the American Society of Echocardiography) and in group B, systolic blood pressure/end-systolic volume index. The results were as follows: Group A: SBSE resulted in significantly lower work load, heart rate, and significantly higher systolic blood pressure, heart hate x systolic blood pressure, end-diastolic volume index, end-systolic volume index, and wall motion score index. SBSE showed wall motion abnormalities in each patient, whereas treadmill did not detect wail motion abnormalities in 4 patients (3 single-vessel; 1 multivessel); of the other 6 patients, 2 showed a lower wall motion score index and 4 did not show any difference in left ventricle kinetics with the 2 methodologies of exercise. Mean acquisition time for postexercise images was 72 +/- 6 seconds. Group B: SBSE resulted in lower work load, heart rate, heart rate x systolic blood pressure, systolic blood pressure/end-systolic volume index, and higher end-diastolic volume index and end-systolic volume index. Systolic blood pressure was similar with SBSE and treadmill testing. In conclusion, our experience suggests SBSE is a highly accurate diagnostic fool for evaluating CAD compared with treadmill testing; the maximum cardiovascular performance can be achieved With lower values of heart rate, suggesting the echo test is more feasible. Treadmill testing could lose important information about the existence, extension, and location of CAD; ire contrast, SBSE detects even small, quickly reversible wall motion abnormalities. (C) 1998 by Excerpta Medica, Inc

PVF velocity pattern in patients with heart failure: Transesophageal echocardiographic assessment

In order to assess the role of the pulmonary venous flow (PVF) velocity pattern in the evaluation of patients with congestive heart failure (CHF), we studied 41 CHF patients by means of transthoracic echocardiography (TTE) and multiplane transesophageal echocardiography (TEE). The etiology of CHF was idiopathic or ischemic dilated cardiomyopathy in 19 patients and hypertensive heart disease in 22. Sixteen subjects without cardiovascular disease were selected as normal controls. PVF peak systolic and peak early diastolic (D) velocities were recorded by TEE and TTE and the systolic fraction (SF) was measured (i.e., the systolic velocity-rime integral - VTI - expressed as a fraction of the sum of systolic and early diastolic VTI). TEE tracings were obtained in all patients and had more laminar-appearing spectral signals, thus were used for analysis. By TTE the mitral flow velocity patterns were also evaluated: peak early diastolic velocity (E), peak velocity at atrial contraction, E velocity normalized for VTI (E/VTI), deceleration time (DT), and left ventricular isovolumic relaxation time (LVIRT). The left ventricular ejection fraction (LVEF) was calculated by two-dimensional echocardiographic images using the modified Simpson method. The SF was lower in CHF patients as compared with normal controls (p 50 cm/s; type B: SF similar to 50%, D > 50 cm/s) were recognized in patients with a low LVEF (type A) and a nearly normal or normal LVEF (type B). Patients with LVEF 40% (33.26 +/- 10.84 vs. 51.00 +/- 4.00%, p 40%. Thus in CHF patients TEE PVF velocity patterns help in distinguishing patients with systolic dysfunction (low LVEF and SF) from patients with predominant diastolic impairment (normal or nearly normal LVEF, high D velocities)

Stratificazione del rischio negli infarti senza onde-Q: ruolo dell'ecocardiografia a riposo e da sforzo

To assess the relation between the extent of myocardial necrosis and the presence of myocardium at risk in myocardial infarction without Q waves (NQMI) we studied by echocardiography the prevalence of jeopardized myocardium in a group of NQMI stratified on the basis of left ventricular wall motion (akinesis, hypokinesis, normal kinesis). We have studied 60 consecutive patients with non-Q myocardial infarction. Patients were examined by 2D echo at rest (V-VI day from the acute episode) and during symptoms limited bicycle ergometric test (ExT) (XX-XXX day). Regional left ventricular wall motion was evaluated as normal or asynergic (severe hypokinetic, akinetic) and the ExT was considered positive in case of new asynergic areas or ECG criteria. 2D echo at rest was technically satisfactory in 56 patients, 19 showed almost an akinetic segment (Aci) 17 had hypokinetic areas (Ipo) and 20 had normal left ventricle kinesis (Norc). Wall motion abnormalities were localized more frequently in the apex and lateral areas. During exercise 2D echo was performed in 46 patients (82%) with 23 positive tests (50%). Stratifying the population on the basis of left ventricle wall motion we observed a major number of positive tests in the group of patients with normal wall motion in comparison with those with asynergic areas at rest (Norc 66.6%, Ipo 35.7%, Aci 42.6% p less than 0.05 Nore vs Ipo and Nore vs Aci) despite the same CAD extension. These data show the heterogeneity of the NQMI that likely includes patients with transmural (asynergy group) and subendocardial MI (normal kinesis group), the latter with a higher degree of myocardium at risk

Role of endogenous opioids on nociceptive threshold in patients with exercise-induced myocardial ischemia.

To evaluate whether endogenous opioids (EO) play a role in the perception of anginal pain, a randomized double blind clinical trial, using naloxone (N) and placebo (P) and measuring beta-endorphin (beta-ep) plasma levels, was performed. We studied 10 patients with angiographically assessed coronary artery disease (CAD) and stable exercise-induced myocardial ischemia (established by 2 preliminary bicycle ergometric tests) of whom 5 symptomatic (SYM) and 5 asymptomatic (ASYM) and 5 subjects without CAD as a control group (CON). On a third exercise test the beta-ep plasma level (fmol/ml) was measured at rest (SYM 5.4 +/- 2.3 vs ASYM 7.2 +/- 2.3 vs CON 6.8 +/- 2.6, NS), at peak exercise (SYM 4.4 +/- 1.8 vs ASYM 8.0 +/- 4.2 and vs CON 6.2 +/- 2.7, NS) and during recovery (SYM 7.5 +/- 4.2 vs ASYM 7.2 +/- 3.0 vs CON 6.7 +/- 2.5, NS). On 2 subsequent tests patients received N (0.2 mg/kg) or P intravenously and chest pain was evaluated on an analogue scale (score from 1 to 10). After N compared to P we observed: an increased perception of chest pain in SYM (6.8 +/- 1.5 vs 4.2 +/- 1.0; p less than 0.01) without significant changes of the ischemic threshold (total work, heart rate-blood pressure product, ST segment changes, 2D-echocardiographic wall motion abnormalities); no modifications in ASYM and CON.(ABSTRACT TRUNCATED AT 250 WORDS