Comparison of impedance cardiography with thermodilution and direct Fick methods for noninvasive measurement of stroke volume and cardiac output during incremental exercise in patients with ischemic cardiomyopathy.

In the last decade, an inexpensive and simple noninvasive method (i.e., transthoracic electrical bioimpedance cardiography, has been tested in healthy subjects and patients with various heart disease for measuring stroke volume and cardiac output at rest and/or during exercise. However, the results are still controversial, especially when measurements are obtained during exercise and data on reproducibility during exercise are lacking. Twenty-five consecutive patients (20 men and 5 women, mean age 48 +/- 9 years) in sinus rhythm with documented coronary artery disease and a previous myocardial infarct were studied. Patients were divided into 2 groups. Group A had ischemic cardiomyopathy, characterized by left ventricular (LV) enlargement and LV ejection fraction depression (35 +/- 8%). Group B had normal LV dimensions and ejection fraction (62 +/- 9%). After a familiarization study, all patients underwent an exercise test with gas exchange analysis and hemodynamic measurements. Stroke volume and cardiac output were simultaneously obtained at rest and at the end of each work rate stage with 3 methods: impedance, thermodilution, and direct Fick. Group A reached a lower peak oxygen uptake (56%), peak work load (60%), and peak systolic blood pressure (69%) than group B. Cardiac output and stroke volume were significantly greater at submaximal and peak exercise in group B than in group A (p < 0.0001). There were no significant differences in stroke volume and cardiac output in the 3 techniques at any matched work rate. There was no significant difference between measurements obtained by 2 experienced observers or between those obtained on 2 exercise tests performed on 2 different days. These results demonstrate that impedance cardiography is a noninvasive, simple, accurate, and reproducible method of measurement of cardiac output and stroke volume over a wide range of workloads.

Iomeprol and iopamidol in cardiac angiography: a randomised, double-blind, parallel-group comparison.

During cardiac angiography, hemodynamic alterations and surface electrocardiographic changes are common, predictable and dose-related adverse reactions to radiocontrast media. High osmolality, inadequate sodium content and local transient hypocalcemia are thought to be the main mechanisms responsible for these untoward cardiovascular effects. The purpose of this double-blind, parallel-group trial was to compare the hemodynamic and electrocardiographic responses to cardiac and selective coronary artery injection of iomeprol 400 (400 mgI/ml) and iopamidol 370 (370 mgI/ml). One-hundred consenting adult inpatients were randomised to receive iomeprol 400 (41 males, nine females; mean age, 56.6 years) or iopamidol 370 (46 males, four females; mean age, 57.6 years). Both agents produced minor and transient hemodynamic and electrophysiological effects. Following left ventriculography, iopamidol 370 produced a significantly greater increase in LVEDP than iomeprol 400 (mean increases after first and second left ventriculogram: 2.5 and 4.6 mmHg with iomeprol 400, 3.3 and 9.9 mmHg with iopamidol 370, P = 0.027). The QT-interval was more affected by iopamidol 370 than by iomeprol 400. However, post-contrast prolongation of the QT-interval was not significant with either agent, nor were there any significant T-wave, ST-segment or RR-interval changes associated with the injection of the test compounds. No serious adverse events occurred throughout the study. Mild pain was complained by only one patient, while most patients reported mild to moderate sensation of heat. Image quality of the vast majority of the procedures was rated as good or excellent in both patient groups.(ABSTRACT TRUNCATED AT 250 WORDS)

[Anti-arrhythmic efficacy of the amiodarone-mexiletine combination in the treatment of resistant complex ventricular arrhythmias]. / Efficacia antiaritmica dell'associazione amiodarone-mexiletina nel trattamento di aritmie ventricolari complesse resistenti.

The efficacy and safety of combined amiodarone and mexiletine treatment was investigated in 16 patients with chronic complex ventricular arrhythmias previously refractory to conventional antiarrhythmic agents and, in a lesser degree, to mexiletine or amiodarone. Many patients had a poor left ventricular function. Oral amiodarone was started using a loading dose of 600 mg daily for one week, 400 mg daily for one week, and a subsequent dosage of 200 mg daily five times a week. After twenty-one days of this treatment mexiletine was administered in combination (600 mg/day orally), if a 24-hour ambulatory ECG had revealed a partial suppression of the ventricular arrhythmias (14 out of 16 patients). On the fourth day of combined amiodarone and mexiletine treatment, analysis of a 24-hour ambulatory ECG showed a marked diminution of the ventricular ectopic activity compared with the pretreatment period. The average percentages of reduction for PVCs and couplets were 88% and 97%. Total suppression of TV runs/24 hr was achieved in all patients. Ventricular arrhythmias relapse was found in all patients during early mexiletine washout (phase 4) and in 12 patients during late mexiletine washout (phase 5). Amiodarone and mexiletine combination did not appear to reduce left ventricular function. Minor side effects occurred in some patients. Follow-up from 3 months to two years (mean 16 months) showed that maintenance treatment had achieved remarkable antiarrhythmic effects (Holter control). However, sudden cardiac death occurred in two patients with very depressed left ventricular function. We conclude that a combined amiodarone and mexiletine treatment effectively reduces the frequency and grade of PVCs and does not impair left ventricular performance. However, it does not prevent sudden cardiac death in patients with poor left ventricular function.

[Echocardiographic and clinical correlations in infectious endocarditis of the left heart]. / Correlazioni ecocardiografiche e cliniche nella endocardite infettiva del cuore sinistro.

UNLABELLED: The echocardiographic features were correlated with the clinical findings and outcome in 35 patients with aortic and/or mitral valve endocarditis. There were 26 males and 9 females with a mean age of 38 years. The infection involved native valves in 27 patients and prosthetic valves in 8 patients. Echocardiographically, fourteen patients had involvement of native aortic valve. All patients in this group required surgical intervention, nine patients during antimicrobial therapy. Congestive heart failure was the clinical indication for valvular replacement. A patient died immediately after surgery from low cardiac output syndrome. Six patients had echocardiographic evidence of aortic and mitral valves involvement. A patient in this group expired before surgery, five underwent surgery because of progressive heart failure (aortic or aortic and mitral valves replacement). Seven patients showed lesions on native mitral valve (6 in this group had prolapse syndrome). A patient died from cerebrovascular embolus, two underwent surgery because of persistent infection and embolic events, four were successfully treated with medical therapy. Among patients with prosthetic valve endocarditis, four showed signs of valvular dehiscence and required surgical intervention, during antimicrobial therapy, from congestive heart failure; one patient expired from recurrent infection. The pathological findings correlated well with echocardiographic findings. CONCLUSIONS: in IE the localization of lesions by echo has prognostic significance: most patients with aortic valve or aortic and mitral valves endocarditis require early surgical intervention because of congestive heart failure. On the contrary, mitral valve involvement carries a better prognosis, requiring less frequently valvular replacement; the patients with echocardiographic signs of prosthetic valve dehiscence require urgent intervention.(ABSTRACT TRUNCATED AT 250 WORDS)

[Echocardiographic diagnosis of aneurysm of Valsalva's sinus with fistulization into the right atrium]. / Diagnosi ecocardiografica dell'aneurisma del seno di Valsalva fistolizzato in atrio destro.

The preoperative diagnosis of an aneurysm of the posterior sinus of Valsalva with rupture into the right atrium was made by echocardiography in a 21-year-old patient. The M-mode echocardiography revealed the following findings: 1) a vibrating anomalous structure, continuous with the aortic wall, was present in the right atrium. The echo-producing mass was the wall of the aneurysm, which adhered to the septal leaflet of the tricuspid valve during early-to-mid systole and had an abrupt posterior motion in late systole. In diastole, the wall of the aneurysm descended into the tricuspid orifice and its motion was similar to that of the septal leaflet of the tricuspid valve; 2) an echocardiographic sweep from the aorta to the left ventricle showed that the posterior wall of the aorta "crossed" the mitral orifice; 3) the pulmonic and tricuspid valves were normal. The 2-D echocardiographic findings gave support to the M-mode diagnosis: 1) in the short-axis view (at the level of the aorta) two lines of echoes came off the right side of the aortic wall and invaded the right atrium. These echoes were produced by the walls of the aneurysm; 2) in the apical four-chamber view the aneurysm descended into the tricuspid orifice in diastole, whereas it was lifted by the septal leaflet of the tricuspid valve in systole. The aneurysm appeared as vibrating lump on the closed tricuspid valve. Recognition of these features provides a potential non-invasive way to diagnose this anomaly. To our knowledge this is the first description of the characteristic echocardiografic picture of an aneurysm of the sinus of Valsalva with rupture into the right atrium.

[Aneurysm of the membranous septum associated with interventricular patency. Echocardiographic study]. / Aneurisma del setto membranoso associato a pervieta' interventricolare. Studio ecocardiografico.

It has been documented by others that spontaneous closure or diminution in size of membranous ventricular septal defect is often associated with aneurysmal formation of the membranous septum. In a series of 51 patients, who underwent cardiac catheterization and cineangiocardiography for evaluation of the severity of a ventricular septal defect, 7 patients showed an aneurysm of the membranous interventricular septum (VSA) associated with a small ventricular septal defect (VSD). M-mode echocardiography was useful in the detection of VSA in 6 of them. Echocardiographic findings were not uniform in all cases. In most instances they consisted of linear echoes, that seemed to come off from the base of the interventricular septum and to protrude within the right ventricle in systole; the echoes from the VSA showed a coarse fluttering. Even if errors can be minimized by a correct technique, anomalous echoes from the VSA might however be confused with those of other anatomical structures (aortic root, tricuspid valve, etc.). M-mode echocardiography seems to be useful for the followup of patients with membranous VSD. The detection of VSA by ultrasonic means should suggest a good prognosis for VSD, possibly avoiding the need for repeat invasive studies.