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

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

Usefulness of transesophageal echocardiography in the assessment of aortic dissection

The acute dissection of the ascending aorta requires prompt and reliable diagnosis to reduce the high risk of mortality; in addition, prognosis is influenced by longterm complications. The aim of this article is to discuss transesophageal echocardiography (TEE) and (1) its diagnostic accuracy in the presurgical evaluation of patients, (2) its role in reducing time of diagnosis and surgery, and (3) its ability to reduce hospital mortality. TEE has also been tested as a screening method in the postsurgical follow-up of these patients. The retrospective investigation concerns a sample of 80 cases of acute dissection of the aorta, submitted for surgical intervention from April 1986 to February 1999. TEE has allowed a precise estimation of aortic diameters and optimal visualization of intimal flap and tear entry with a fine distinction between true and false lumen. A direct comparison of the results of TEE and of transthoracic echocardiography has demonstrated that some elements (visualization of flap and diameters in descending aorta, sites of entry and reentry, direction of let trough intimal tears, phasic intimal flap movement, diastolic collapse of flap on the valvular plane, false lumen thrombosis, coronary involvement, intramural hematoma, and aortic fissuration) were identified only by TEE, whereas other additional diagnostic elements (cardiac tamponade, aortic valve insufficiency, left ventricular function) show a similar pattern of significance. Routine employment of this method has confirmed a reduction of hospitalization time (about 1.5 hours of waiting time), and hospital mortality has changed from 42.8% to 17.3%. In the follow-up of patients operated on for aortic dissection, fundamental information may be obtained from TEE (assessment of the progression of thrombosis in the false lumen with its complete obliteration and modifications in aortic diameter with a consequent, possible worsening of aortic valve insufficiency). In conclusion, our study demonstrated that TEE may provide fast and efficient detection of acute aortic dissection. In the postsurgical follow-up, TEE has confirmed detection of major complications that can influence long-term prognosis and may be proposed as a method with easy access-one that is repeatable and inexpensive for the screening of aortic dissection surgical patients. (C) 2000 by Excerpta Medica, Inc

Identification of viable myocardium in patients with chronic coronary artery disease and left ventricular dysfunction: role of MRI.

Nineteen patients (16 men and 3 women, mean age 51 years) with previous anterior myocardial infarction and severe stenosis (> or = 90%) of the left anterior descending coronary artery were studied by magnetic resonance imaging (MRI) without and with contrast media to verify the capability of MRI in identifying viable myocardium in areas of severe systolic dysfunction. In corresponding left ventricular segments, a comparison was made between regional signal intensities (SI) determined on MRI images before and 4, 8, 12, and 30 minutes after administration of paramagnetic contrast media (gadolinium diethylenetriaminepentaacetic acid, 0.4 mmol/kg intravenously) and metabolic parameters determined by iodine 123 phenylpentadecanoic acid (IPPA) scintigraphy. The SI and the time of maximum postcontrast enhancement were analyzed by dividing the left ventricle into 11 segments. Each segment was classified as normal (group 1, n = 116), hibernating (group 2, n = 50), or necrotic (group 3, n = 43) on the basis of the IPPA washout rate (> 30%, 10% to 30%, and < 10%, respectively). Regional SI demonstrated significant differences in absolute values at 12 minutes (group 3: 1.62 +/- 0.58 vs group 1: 1.32 +/- 0.52, p < 0.01, and vs group 2: 1.34 +/- 0.48, p < 0.05) and at 30 minutes (group 3: 1.71 +/- 0.47 vs group 1: 1.21 +/- 0.55, p < 0.01, and vs group 2: 1.49 +/- 0.57, p < 0.05) and in temporal distribution. These results suggest that MRI has a potential role in differentiating viable from necrotic myocardium in patients with chronic severe systolic dysfunction

The diagnostic accuracy of pharmacological stress echocardiography for the assessment of coronary artery disease: a meta-analysis

<p>Abstract</p> <p>Background</p> <p>Recent American Heart Association/American College of Cardiology guidelines state that "dobutamine stress echo has substantially higher sensitivity than vasodilator stress echo for detection of coronary artery stenosis" while the European Society of Cardiology guidelines and the European Association of Echocardiography recommendations conclude that "the two tests have very similar applications". Who is right?</p> <p>Aim</p> <p>To evaluate the diagnostic accuracy of dobutamine versus dipyridamole stress echocardiography through an evidence-based approach.</p> <p>Methods</p> <p>From PubMed search, we identified all papers with coronary angiographic verification and head-to-head comparison of dobutamine stress echo (40 mcg/kg/min ± atropine) versus dipyridamole stress echo performed with state-of-the art protocols (either 0.84 mg/kg in 10' plus atropine, or 0.84 mg/kg in 6' without atropine). A total of 5 papers have been found. Pooled weight meta-analysis was performed.</p> <p>Results</p> <p>the 5 analyzed papers recruited 435 patients, 299 with and 136 without angiographically assessed coronary artery disease (quantitatively assessed stenosis > 50%). Dipyridamole and dobutamine showed similar accuracy (87%, 95% confidence intervals, CI, 83–90, vs. 84%, CI, 80–88, p = 0.48), sensitivity (85%, CI 80–89, vs. 86%, CI 78–91, p = 0.81) and specificity (89%, CI 82–94 vs. 86%, CI 75–89, p = 0.15).</p> <p>Conclusion</p> <p>When state-of-the art protocols are considered, dipyridamole and dobutamine stress echo have similar accuracy, specificity and – most importantly – sensitivity for detection of CAD. European recommendations concluding that "<it>dobutamine and vasodilators (at appropriately high doses) are equally potent ischemic stressors for inducing wall motion abnormalities in presence of a critical coronary artery stenosis</it>" are evidence-based.</p

The 20 year evolution of dobutamine stress cardiovascular magnetic resonance

Over the past 20 years, investigators world-wide have developed and utilized dobutamine magnetic resonance stress testing procedures for the purpose of identifying ischemia, viability, and cardiac prognosis. This article traces these developments and reviews the data utilized to substantiate this relatively new noninvasive imaging procedure

[Supraventricular hyperkinetic arrhythmias in acute myocardial infarct: their prognostic assessment and correlation with the echocardiographic evolution].

To assess the prognostic significance of supraventricular tachyarrhythmias (SVTA) during acute myocardial infarction (AMI), we studied 388 patients with first AMI, without ventricular preexcitation or chronic atrial fibrillation. The prevalence of SVTA was 14% (56/388), including atrial fibrillation (57%), atrial flutter (22%), polyfocal atrial tachycardia (14%), monofocal atrial tachycardia (7%). The arrhythmia appeared within 72 hours from the onset of chest pain in 61% of patients (early SVTA 72 hours). Patients with SVTA (Group I n = 56) and without SVTA (Group II n = 232) were similar regarding prevalence of hypertension, dyslipidemia, diabetes, site of infarction and fibrinolysis, but SVTA was associated with a significant increase in death (Group I 18% versus Group II 9%; p < 0.05) and complications as pulmonary oedema and cardiogenic shock (Group I 25% versus Group II 14%; p < 0.05). Left atrial dimensions (LAD), end-diastolic left ventricular volume (EDLVV), end-systolic left ventricular volume (ESLVV) and echo-score, evaluated at admission, were not different between Group I and II (LAD 41.3 +/- 6 mm versus 40.1 +/- 5 mm, NS; EDLVV 181 +/- 34 ml versus 173 +/- 30 ml, NS; ESLVV 80 +/- 21 ml versus 75 +/- 18 ml, NS; echo-score 6.7 +/- 3.1 versus 6 +/- 2.7, NS) while pre-discharge echo-grams in Group I showed a trend towards the increase in volumes and echo-score (EDLVV from 181 +/- 34 ml to 194 +/- 36 ml, p = 0.052; ESLVV from 80 +/- 23 ml to 88 +/- 23 ml, p = 0.051; echo-score from 6.7 +/- 3.1 to 7.8 +/- 3.3, p = 0.070).(ABSTRACT TRUNCATED AT 250 WORDS

[Coronary morphometry in essential arterial hypertension].

To evaluate the prevalence and pathophysiological significance of I and II order coronary arteries with a tortuous course we reviewed 1530 coronaroventriculographies. Tortuosity was identified by the finding of 4 bendings at least, with an angle less than 60 degrees, present both in systole and in diastole. Morphologic alteration was found in 64% of hypertensives and in 13% only of non hypertensive coronaropathic patients; the prevalence was 58% in valvular aortic stenosis (being 16% in the remaining valvulopathies) and 100% in hypertrophic cardiomyopathy. No normal subject showed coronary tortuosity. A retrospective analysis of patients' echocardiograms pointed out a significant association between tortuosity and concentric left ventricular hypertrophy, expressed by mass/volume ratios clearly above the normal values (1 +/- 0.2): 1.6 +/- 0.17 in hypertensives, 2.1 +/- 0.2 in aortic stenoses and 2.6 +/- 0.2 in hypertrophic cardiomyopathy. Among hypertensive subjects, we selected a group with essential systemic hypertension and no coronary stenoses nor dysmetabolic diseases: this group was divided into 2 subgroups on the basis of presence or absence of coronary tortuosity. A comparison of these subgroups for age, echocardiographic parameters (left ventricular mass index, mass, mass/volume ratio, end systolic stress) and hemodynamic data (end diastolic left ventricular pressure, gradient: mean aortic pressure--end diastolic left ventricular pressure) showed no significant difference between patients with or without tortuosity. Moreover those patients were evaluated by ergometric test, echo stress, cold pressor test and dipyridamole stress test: a significantly higher prevalence of myocardial ischemia was found in the subgroup with tortuous vessels (63% versus 11%, p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS

Influence of reperfusion induced by thrombolytic treatment on natural history of left ventricular regional wall motion abnormality in acute myocardial infarction.

Although several studies have investigated left ventricular (LV) function after reperfusion interventions, it is still unclear whether benefits result from successful therapy or whether such benefits only reflect the natural history of a subgroup of patients with acute myocardial infarction (AMI). This study evaluates the unique effect of thrombolytic therapy on the natural history of regional LV wall motion dysfunction. One hundred seventy-six patients with AMI were studied: 82 patients (group A) underwent conventional treatment and 94 (group B) thrombolytic therapy. LV regional improvement, evaluated by changes in echo score between admission and predischarge examination, was present more frequently in group B (28%) than in group A (17%). Furthermore, improved patients in group B had higher admission echo scores (7.5 +/- 3.5 vs 6.3 +/- 3.1), a prevalence of anterior AMI (68 vs 30.1%) and a higher rate of coronary patency (92 vs 58% in patients who had no improvement). In group A patients the rate of coronary patency was similar in those who did (46.1%) and did not have (36.1%) improvement. Observations at 12 to 18 months showed similar data in group A patients and in group B patients without improvement, whereas a marginal additional improvement was observed in group B patients who had in-hospital improvement. These observations demonstrate that LV function recovery is more frequent and marked in treated than in untreated patients. Follow-up results suggest a prolonged beneficial effect of thrombolytic treatment on LV function. The highest rate of coronary patency in improved group B patients underline the role of reperfusion on natural history of LV dysfunction after AMI