In vitro identification of different degrees of mitral valve disease by online evaluation of radiofrequency ultrasound signal.

Sixty five mitral valves were studied in vitro with a 2.25 MHz transducer. Radiofrequency signals were analysed by a microprocessor system (implemented on an M-mode commercially available echocardiography) for online evaluation of ultrasonic backscatter (8 bits of amplitude resolution, 40 MHz sampling rate, 1 microsecond acquisition gate). The integrated value of the rectified signal amplitude was expressed as the integrated backscatter index (in db). The highest value recorded with ultrasonic scanning of each sample was taken as representative of that specimen. Calcification of mitral valves was assessed by radiography (24 mitral valves). Non-calcified mitral calves underwent pathological examination, and fibrotic valves (22 mitral valves) were differentiated from normal valves (19 mitral valves). A statistically significant (p less than 0.005) difference was recorded among the three groups for the index maximal value: calcific -7.4(3.1) db (mean(SD)), fibrotic -18.9(4.9) db, and normal -37.9(7.6) db. In conclusion, a microprocessor based system for online evaluation of radiofrequency ultrasonic signals, which may also be feasible for in vivo studies, provided a clear differentiation in vitro of calcific, fibrotic, and normal mitral valves.

Histologic evidence of myocardial damage in apparently healthy subjects with ventricular arrhythmias and myocardial dysfunction.

The association of ventricular arrhythmias and myocardial dysfunction could be considered an early step toward cardiomyopathy; therefore, we studied 28 patients in NYHA class I and II, characterized by complex ventricular arrhythmias (VA) on 24-h Holter monitoring and volumetric and/or contractile abnormalities on a standard two-dimensional echocardiogram (2-D echo). All patients underwent radioisotopic angiography, 20 patients complete hemodynamic study, and 15 patients endomyocardial biopsy. Ambulatory ECG monitoring showed the presence of frequent premature ventricular contractions in 14 patients (50%) and episodes of ventricular tachycardia in 16 patients (57%). 2-D echo showed mono- or biventricular enlargement and dyssynergies in 25 patients (89%) (left ventricle in 6, right ventricle in 11, both in 8). Two patients showed only left ventricle enlargement and one patient isolated left ventricular dyssynergies. Radioisotopic angiography showed mono- or biventricular ejection fraction reduction in 24 patients (85%) and regional dyssynergies in 24 patients (85%) in accordance with 2-D echo. Hemodynamic study showed in all patients normal coronary arteries, and right and left angiography confirmed enlargement and/or regional dyssynergies. Endomyocardial biopsy was abnormal in 11 of 15 patients: various degrees of hypertrophy, parcellar fibrosis, and adipogenic infiltration were found. Our preliminary data suggest that the simultaneous occurrence of ventricular arrhythmias and ventricular dyssynergies and/or enlargement in patients without apparent clinical heart disease may represent an early stage of dilated cardiomyopathy.

[Association between parachute mitral valve and Down's syndrome. Report of a case]. / Associazione di valvola mitrale a paracadute e sindrome di Down. Descrizione di un caso.

The trisomy 21 form of Down's syndrome is the most common human chromosomal aberration. Congenital heart disease is found in as many as 50 per cent of patients with this disorder. The two most common cardiac lesions in Down's syndrome are septal ventricular defect and endocardial cushion defect. Secundum atrial septal defect, tetralogy of Fallot and isolated patent ductus arteriosus are also observed in these Down's patients. Transposition of great arteries and coarctation of the aorta are rarely seen. Most patients having Down's syndrome with congenital heart disease have a single lesion. However, as many as 30 per cent may have multiple cardiac defects. Parachute mitral valve is a rare congenital mitral defect: a single papillary muscle in the left ventricle is the hallmark of this lesion. A parachute mitral valve is frequently associated with other left heart disorders such as supravalvular mitral ring, abnormal and stenosed mitral valve, subaortic stenosis and coarctation of the aorta, thus constituting either a complete form of Shone's complex (when all 4 components are present) or an incomplete form when there are fewer. The aim of the present report is to describe the connection between Down's syndrome and isolated, non-stenosed parachute mitral valve, which has never been reported before.

[Pseudoaneurysm of a branch of the internal mammary artery in a case operated on for aortic coarctation]. / Pseudoaneurisma di un ramo dell'arteria mammaria interna in un caso di coartazione aortica operata.

False aneurysm of the internal mammary artery (IMA) is a rare complication of closure of median sternotomy by peristernal wiring. In this report a case of a false aneurysm of a branch of the internal mammary artery following a surgical repair of a complex cardiac anomaly in a patient with a previously dilated mammary artery system for pre-existing coarctation of the aorta is described. In our opinion a special attention has to be given to the course of the IMA and its collaterals whenever a median sternotomy is required to treat an aortic coarctation or its associated diseases, considering the possibility of ligation of vessels at risk of being damaged by the sutures used for closure of the sternal and rectus sheath incisions.

[Ambulatory ECG in the peroperative period]. / L'ECG dinamico nel periodo perioperatorio.

The clinical recognition of perioperative myocardial necrosis represents one of the clue factors in the management of cardiac surgical patients (pts). This study was performed to determine whether there is any relationship between reperfusion ventricular fibrillation and/or ST-segment elevation and postoperative enzymatic release. Serum enzyme levels and ECG were monitored during and after cardiac operations in 23 pts (15 for valvular replacement and 8 for aortocoronary bypass graft). After aortic unclamping only 6 pts showed stable rhythm. Of the 17 pts who developed ventricular fibrillation 10 showed ST-segment elevation (83% of the 12 pts with ST-segment elevation). Although no significant difference was observed, pts with ST-segment elevation showed higher average enzyme (CK, CKMB) levels. Pts who had valvular replacement showed significantly higher serum CK and CKMB levels. Of the 4 pts who showed a second enzymatic peak, one died and another one presented complex ventricular arrhythmias. No correlation was observed between electrocardiographic data and post-operative enzymatic release. New theories concerning oxygen free radical generation during and after cardiopulmonary by-pass, with the related therapeutic perspectives, are discussed.

Cardiac damage due to nonpenetrating trauma. Report of four cases.

Four examples of cardiac damage secondary to nonpenetrating trauma in road accidents are described. Two patients had interventricular septal defect and other two had tricuspid insufficiency. In all four cases the lesion was not recognized at the time of the accident but became clinically important later. The time interval between trauma and surgery was one month to thirteen years. After surgical treatment, all four patients have continued to be asymptomatic.

[Ambulatory electrocardiography in the screening of patients with palpitations]. / L'elettrocardiografia dinamica nello screening del paziente con palpitazioni.

The role of 24 hour Holter monitoring in the screening of patients complaining of palpitations is reviewed. The term "palpitations", although not always unequivocally used, implies the presence of an arrhythmia. The clinical-instrumental correlation of an intermittent symptom is made possible by continuous electrocardiographic monitoring. Answers to be expected from a 24 hour Holter monitoring in order to achieve an early characterization of the arrhythmia are related to: site of origin, incidence, circadian distribution, prognostic stratification, events aggregation, presence of other asymptomatic abnormalities (rhythm, ST-T).

Evaluation of rate-responsive pacemakers by transesophageal Holter monitoring of spontaneous atrial rate.

One of the most important problems in rate responsive (RR) pacing is the clinical experimental evaluation of the reliability of various sensors. In particular, it is difficult to test their sensitivity and specificity during daily activity of the patients. Atrial rate, when present and normal, is the most physiological marker of metabolic requirements, but sometimes it is impossible to analyze the P wave in ventricular paced rhythm during routinely performed tests (e.g., ergometric test and 24-hour Holter monitoring). During various physical activities, we monitored atrial electrograms on an esophageal lead on the first channel of a standard Holter tape recorder; on the second channel a surface ECG lead was recorded. We selected 10 patients with high grade heart block and normal sinus node function paced in RR-VVI mode. RR pacing was obtained using various sensors (body activity, blood temperature, spike-T interval, minute ventilation). The good quality of recording allowed an easy evaluation of atrial and ventricular rates. In four cases an appropriate increase in heart rate was documented; sensitivity threshold and/or rate response slope were reprogrammed when indicated. The pacing rate of one patient did not parallel the atrial rate during walking only. In three cases, we observed a delay in the ventricular rate increase, with ventricular rate decreasing at peak exercise despite further atrial rate increase. In the last two patients, we observed inappropriate pacing response; pacing rate increased later and to a lower level than the atrial one. This new method is applied easily and appears reliable to evaluate the response of RR pacemakers to individual metabolic needs.(ABSTRACT TRUNCATED AT 250 WORDS)