Cardiac amyloidosis. Invasive and noninvasive diagnosis

Aim of this study is the analysis of clinical, morphologic and haemodynamic features of cardiac amyloidosis. Cardiac amyloidosis was demonstrated histologically in 7 of our patients: in 6 by endomyocardial biopsy during cardiac catheterization, in one at autopsy. The clinical picture was characterized in every patient by signs and symptoms of congestive heart failure. The electrocardiogram showed several non specific signs: low voltage of the QRS complexes, both in peripheral (4/7) and precordial leads (7/7 cases); marked leftward and upward deviation of the QRS axis (6/7 cases); first degree A-V block (5/7); abnormal Q waves (7/7). M-mode and two-dimensional echocardiography invariably demonstrated a typical pattern: a non dilated left ventricle with thickened and hyper-refractile walls, and usually a slight-moderate diffuse hypokinesia. Other common features were a thickening of right ventricular walls, interatrial septum, and atrioventricular and semilunar valves. Computerized analysis of the M-mode tracings disclosed a marked impairment of the indexes of both systolic and diastolic ventricular function in all patients. By correlating electrocardiographic and echocardiographic data, we found in every case a striking disproportion between the low QRS voltage and the high muscle cross-sectional area (an echocardiographic index of left ventricular mass): this pattern appears to be highly suggestive of infiltrative heart disease. Cardiac catheterization (performed in 6 cases) showed an increase of left ventricular (6/6) and right ventricular (5/6) end-diastolic pressure, with a dip plateau pattern in some cases (4/6 of the left, 2/6 in the right ventricle). The cardiac index was decreased in 3/6 cases. Left ventricular angiography confirmed the echocardiographic data of normal volumes and a slight-moderate decrease of the ejection fraction. We conclude that cardiac amyloidosis usually mimics a restrictive cardiomyopathy (severe congestive heart failure with increased ventricular filling pressures, in the absence of severe systolic ventricular dysfunction). This disease can be suspected clinically by the correlation of the clinical, electrocardiographic and echocardiographic data. The final diagnosis requires an endomyocardial biopsy.     

Tissue Doppler imaging in the normal fetus

Tissue Doppler imaging is a new non-invasive method that derives measurements of relaxation velocities directly from the myocardium. This approach to studying myocardial velocities offers the potential for quantitative assessment of diastolic ventricular function. Data on myocardial tissue velocities in normal fetuses have not been established. We measured motion velocities of the left ventricular posterior wall, right ventricular anterior wall, interventricular septum along the long axis in 30 normal fetuses aged 19-38 weeks gestation (mean, 26.3+/-6.0 weeks). In all fetuses, peak myocardial velocities during early diastole (EW) and atrial contraction (AW) waves were recorded. The mean values for EW, AW, and E/AW of left ventricle were 5.4+/-1.7, 7.0+/-1.4 cm/s, and 0.77+/-0.19, respectively, and those of right ventricle were 5.5+/-1.5, 7.8+/-1.5 cm/s, and 0.70+/-0.14, respectively. The EW(4.1+/-1.0 cm/s) and the AW (5.3+/-0.8 cm/s) of the interventricular septum were significantly lower than those of the left and right ventricular walls (P<0.01). The EW and E/AW of the left ventricular wall increased significantly with increasing gestational age (r=0.81 and 0.85, respectively, P<0.01). Similar changes were observed in the myocardial velocities of the right ventricular wall. The EW and E/AW of the interventricular septum also increased significantly with age (r=0.63 and 0.78, respectively, P<0.01). However, AW of the interventricular septum showed little changes. In both ventricles, there were significant correlations between tissue Doppler E/AW and pulsed Doppler E/A (LV, r=0.56; and RV, r=0.60, P<0.01). Assessment of myocardial tissue velocities in fetuses is feasible with tissue Doppler imaging. Age-related alterations in tissue Doppler velocities may suggest age-related maturational changes in diastolic function.     

Use of pharmaceuticals in noninvasive cardiovascular diagnosis

A number of pharmaceuticals are employed as diagnostic agents for cardiovascular diseases. Four groups of agents are reviewed here: 1) vasoactive substances employed as adjuncts to physical maneuvers in diagnosis of structural heart disease; 2) vasodilators used to produce heterogeneity of coronary flow; 3) sympathomimetic agents simulating the effects of exercise on the heart for the purpose of detection of coronary artery stenosis; and 4) ultrasonic contrast agents used to enhance myocardial imaging for the assessment of segmental wall motion. In the first group are amyl nitrate, a vasodilator, and methoxamine and phenylephrine, both vasopressors. The vasodilators of the second group are dipyridamole and adenosine. When combined with scintigraphic perfusion imaging or with echocardiographic assessment of segmental wall motion, these agents can detect single- or multiple-vessel coronary artery disease with sensitivity and specificity comparable to submaximal exercise. They are especially useful for preoperative risk assessment before noncardiac surgery. The sympathomimetic agents of the third group, dobutamine and arbutamine, increase myocardial contractility and heart rate, and dilate the peripheral vasculature. As with the vasodilators, when combined with nuclear or echocardiographic techniques they are equivalent to exercise in detection of coronary disease. They are especially useful in patients with bronchospastic disease and for assessment of myocardial viability. Agents from groups 2 and 3 have acceptable side-effect and safety profiles. The last group reviewed includes echocardiographic contrast agents that, in this investigative setting, are employed to enhance detection of segmental wall motion when used with agents from groups 2 and 3.     

Innovations in cardiovascular imaging

Cardiovascular diseases are culpable for the majority of mortalities the world over, hence the significance of advances in preventive medicine and imaging. Cardiovascular imaging constitutes the cornerstone of not only early but also precise diagnoses. Indeed, advanced imaging enables cardiologists to make efficacious management plans for various heart conditions. The present article discusses essential innovations in cardiovascular imaging.     

Changes in noninvasive cardiovascular parameters by inpatient weight reduction

36 normotensive obese and 23 hypertensive obese were treated with an isokaloric reduction diet of 800 kcal/a day under clinical conditions over a 4-week span. Blood pressure and cardiac performance were investigated by means of non-invasive techniques such as systolic time intervals (STI) and calculated indices. A significant decrease was established in systolic time intervals such as left ventricular ejection time and total electromechanical systole, systolic and diastolic blood pressure, myocardial oxygen consumption and cardiac output. Heart rate, preejection index and stroke volume were not diminished under dietary treatment. No decrease of all parameters was found in obese normotensives with a weight reduction greater than 5% after dietary treatment.     

Invasive imaging of the coronary atherosclerotic plaque

Coronary atherosclerosis has a high prevalence and is known as the leading cause of death worldwide. Clinically, coronary atherosclerosis is routinely evaluated by coronary angiography, which provides a luminogram of the coronary artery and allows for recognizing lumen narrowing. However, angiography does not allow for the direct assessment of the disease process within the coronary vessel wall. Today, a number of catheter-based imaging methods can overcome this shortcoming and provide physicians with additional information on specific morphological components of atherosclerotic lesions. This article discusses the abilities of intravascular imaging techniques such as intravascular ultrasound (IVUS), IVUS-VH, iMAP, integrated backscatter-IVUS, intravascular optical coherence tomography, near-infrared spectroscopy and angioscopy, to diagnose coronary atherosclerosis and their potential to guide clinical decision making.     

New noninvasive imaging technologies in coronary artery disease

Coronary artery disease affects a large population. Recent emphasis on primary and secondary prevention has made an impact on the detection of atherosclerosis, yet the incidence of acute coronary syndromes continues to increase. This has steered the cardiology community toward improving and developing new imaging techniques that are capable of detecting disease at a very early preclinical state. Coronary CT angiography is capable of characterizing plaques and detecting eccentric lesions that would not appear on stress testing or cardiac catheterization. Cardiac MRI provides high-resolution imaging of plaques in addition to tissue characterization without the ionizing radiation associated with other imaging techniques. Positron emission tomography is a rapidly growing imaging tool that detects inflammation associated with coronary atherosclerosis. In the near future, these new noninvasive modalities will play an intricate part in primary prevention and in diagnosis and treatment follow-up.