[The role of the echo-dipyridamole test in the diagnosis of coronary disease in patients with associated aortic stenosis]. / Il ruolo del test eco-dipiridamolo nella diagnosi di coronaropatia in pazienti con stenosi aortica associata.

BACKGROUND: Coronary vasodilator reserve is often significantly impaired in patients with aortic stenosis by several mechanisms: coronary artery disease, left ventricular hypertrophy, increase in cardiac chamber stiffness. The aim of this study was to evaluate the feasibility and the diagnostic accuracy of the dipyridamole echocardiography test in the diagnosis of coronary artery disease in patients with aortic stenosis. METHODS: Forty patients (26 males, 14 females, mean age 69 +/- 8.9 years) with aortic stenosis (mean valve area 0.7 +/- 0.3 cm2 calculated by the continuity equation) were studied by two-dimensional echocardiography during dipyridamole infusion up to 0.84 mg/kg over 10 min. Wall motion was graded for each segment as normal, hypokinetic, akinetic and dyskinetic. Dipyridamole echocardiography was considered positive for ischemia if wall motion in at least one segment worsened by at least one degree point level compared to wall motion at rest. All patients underwent coronary angiography (mean time after dipyridamole echocardiography 7 +/- 3 days). The chi 2 test and Student's t-test for paired data were used; a p value of < 0.05 was considered as statistically significant. RESULTS: Only one dipyridamole echocardiography was interrupted because of supraventricular tachycardia appearance. Nine patients showed new asynergy areas during dipyridamole echocardiography; 19 patients had ST segment downsloping of > or = 1 mm during dipyridamole infusion; 12 patients experienced angina during the test. Angiography showed a significant coronary stenosis in 10 patients. Dipyridamole echocardiography sensitivity was 80%, specificity was 96%; specificity of ST segment downsloping and angina were 63 and 76% respectively. CONCLUSIONS: Dipyridamole echocardiography in patients with aortic stenosis is safe and feasible with good sensitivity and better specificity. Our study suggests also that dipyridamole echocardiography test is able to rule out patients with aortic stenosis and coronary artery disease as opposed to those with angina without organic stenosis of the coronary vessels.

Role of sinus node artery disease in sick sinus syndrome in inferior wall acute myocardial infarction.

This study was undertaken to evaluate a possible role of sinus node (SN) artery disease in the pathogenesis of sick sinus syndrome (SSS) in patients with an inferior wall acute myocardial infarction (AMI). Coronary angiography and electrophysiologic studies of the SN, both in the basal state and after pharmacologic autonomic blockade, were performed in 23 study patients (mean age 60 years) with SSS and a previous inferior wall AMI and in another 23 control patients (mean age 57 years) with normal sinus rate and a previous inferior AMI. Stenosis of the SN artery (or that proximal to its origin) greater than 50% was present in 13 study patients (56%) and in 8 control patients (34%) (p less than 0.05). In the study group, the intrinsic heart rate was abnormal in 5 of the 6 patients (83%) with severe SN artery stenosis (greater than or equal to 75% narrowing), in 3 of the 7 (43%) with moderate stenosis (50 to 75% narrowing) and in 3 of the 10 (30%) with insignificant stenosis (less than 50% narrowing). In the study group, the correlation between the SN measures (heart rate, corrected SN recovery time and sinoatrial conduction time) and the severity of SN artery stenosis was good after autonomic blockade (r between 0.59 and 0.64) and poor in the basal state. These data provide evidence for a role of SN artery disease in the pathogenesis of SSS in patients with an inferior wall AMI.

Relationship between the most proximal His bundle and the morphology of intracavitary pressure curves.

A precise localization of the most proximal His bundle (HB) is useful both for diagnostic and for therapeutic purposes, allowing the modification of atrioventricular (AV) nodal conduction. For selective diagnosis a bipolar lead is utilized; for therapy, a unipolar lead. The aim of the present study was to determine the relationship between the most proximal HB and the morphology of intracavitary pressure curves. In 15 patients (aged 64 +/- 10 years), both bipolar and unipolar H-V intervals were continuously recorded while gradually withdrawing the catheter, which detected the pressure at its tip, from the right ventricle to the atrium. The longest bipolar H-V was 55.5 +/- 13 ms and the shortest 44.5 +/- 11 ms (P less than 0.001); the longest unipolar H-V was 56.5 +/- 14 ms and the shortest 46.2 +/- 11 ms (P less than 0.001). During unipolar recording, H deflection was present in all patients at the same time as ventricular, transvalvular and atrial pressure curves; during bipolar recording, the H electrogram was not present in only one patient concomitantly with the atrial curve. During bipolar recording, the atrial H-V interval was greater than transvalvular H-V in nine patients (mean differences: 6 +/- 2 ms) and they were equal in five; with unipolar recording the atrial H-V interval was greater than transvalvular H-V in 13 patients (mean difference: 8 +/- 6 ms) and they were equal in two. In all patients, the H wave amplitude diminished from the transvalvular area to the atrial one.(ABSTRACT TRUNCATED AT 250 WORDS)

Does intravenous streptokinase therapy facilitate the formation of anti-heart antibodies in acute myocardial infarction?

Streptokinase (SK), a nonenzymatic protein produced by group C beta haemolytic streptococci, is a potent antigen. It is used worldwide as a thrombolytic agent in the treatment of acute myocardial infarction (AMI). Specific antiheart antibodies (AHA) have been found with a significantly high incidence in patients with AMI, and after streptococcal infection as a result of stimulation by constituents of the group A streptococci antigenically cross-reactive with sarcolemmal portion of the muscle fiber of the heart. Since there may be partial antigenic identity of group C streptococcal membranes with membranes isolated from group A streptococci, we have designed a prospective study to evaluate the incidence of serum AHA (and of other organ-specific and non-organ-specific antibodies) in 36 patients with AMI, 14 of whom treated with SK. AHA, of IgG class, were of the sarcolemmal-subsarcolemmal type, and did not fix complement. They were found in 4/36 patients already on admission; of the 32 patients negative, none developed AHA later, on days 7, 15 and 21 of hospitalization, also after treatment with SK (in 14 cases). There was no significant difference either within or between the two SK-treated and non-SK-treated groups also with regard to the incidence of organ-specific and non-organ-specific autoantibodies. These findings do suggest that the intravenous SK therapy does not facilitate the formation of AHA in AMI.

[The Italian experience with lithium pacemaker (author's transl)]. / L'esperienza italiana con i pacemaker al litio.

After explaining the concept and evolution of lithium-anode batteries, and the various types in use at present as power sources for pulse generators, the Authors examine the Italian studies, including pacemaker's clinical follow-up, technical trials and productions. In fact the first pulse-generators, powered by the best known battery prototypes, i.e. old Lithium-Iodine cell 702 C,P, and E, and Lithium-Silver Chromate cell Li 210 and Li 355, were implanted respectively in 1972, 1973 and 1974, at the Cardiology Department, Ferrara, Italy. The detailed account and analysis of the data supplied by both Italian and Foreign manufacturers, together with the observations furnished by 24 Pacing-Centres--2845 pacemakers implanted for a total amount of 31,794 months/pacemaker out of 8,475 pacemakers supplied for 77,606 months/pacemaker up to June, 30, 1977-indicate a promising future for the development of such pulse-generators. Indeed the latest improved power sources associated with the best and most reliable electronic and electrode pacing systems, already allow the manufactures to produce small, comfortable and long-term pacemakers. Furthermore the significant reduction in periodic controls and replacements, if actually needed, seems sufficient in itself to counterbalance the initial high cost. Thus, medical staff and equipment can be utilized for other purposes.

[Apparently unusual causes of inhibition of demand unipolar pacemakers (author's transl)]. / Cause apparentemente insolite di inibizione dei pacemakers unipolari a domanda.

An unusual behaviour observed in five demand endoventricular unipolar pacemakers is reported: the pacing were inhibited by coughing, deep inspirations and Valsalva manoeuvre. The findings allowed to point following remarks: a) the inhibition is related to myopotentials caused by respiratory movements which involve a large number of thoracic skeletal muscles; b) the myopotential characteristics may be differents in different patients; c) even electronic sensing characteristics may be slightly different in the same kinds and models of the same manufacturer.

[Electrode surface areas, pulse duration and stimulation threshold. Acute and chronic study with endocardial unipolar electrodes (author's transl)]. / Superficie elettrodica, durata dell'impulso e soglia di stimolazione. Studio acuto e cronico con elettrodi endocavitari unipolari

Acute and chronic voltage-threshold of cardiac stimulation was studied in patients with complete A-V block. Endocardial unipolar electrode with three different cathodial surface areas were used (54, 22 and 12 sqmm), and tested with rectangular stimulus of variable duration (from 0.2 to 3.5 msec.). The results show that the threshold values, at first implantation and at pulse-generator replacements, are low when short-duration stimulus and smaller electrode surface area are used. The practical advantages of this study are evident.

[Idiopathic sick sinus syndrome with a-v and intraventricular conduction disturbances in a child. (first report in childhood) (author's transl)]. / "Sick sinus syndrome" idiopatica con turbe della conduzione A-V ed intraventricolare in un bambino. Primo rapporto in età pediatrica.

This report presents a ten-year old child suffering from sick sinus syndrome, in the "Bradycardia-tac hycardia-asystole" variant. A long observation and an ECG made when he was 7 have never shown a sinusal rhythm. An involvement of the A-V node is also present, made clear by a block of the second degree with not very high atrial rates and by prolonged refractory periods, as well as an involvement of the intraventricular conduction, made evident by an incomplete right bundle branch block and by a long refractory period of the anterior fascicle. The clinical, laboratory and hemodynamic data excluded either a congenital or an acquired cardiopathy. The ECGs of the patient's relatives excluded a familiar type of S.S.S. It is, therefore, an idiopathic S.S.S., which is very rare in children. The nosological set in the still vague field of the idiopathic degenerations of the conduction tissue is discussed.

[The reliability of several polycardiographic indices in the quantitative evaluation of mitral stenosis (author's transl)]. / Attendibilita' di alcuni indici poligrafici nella valutazione quantitativa della stenosi mitralica

In 21 patients with pure, isolated mitral stenosis, four hemodynamic parameters were studied. They were obtained by left and right cardiac catheterization and were: the mean pulmonary artery wedge pressure, the diastolic mitral gradient, the stroke volume and the mitral valve area with one or more parametres amd polycardiographic indices, to verify the reliability of the quantitative evaluation of mitral stenosis by noninvasive methods. The polycardiographic indices of Yigitbasi (r = 0.76) and Wells (r = 0.65) were best correlated with the mean pulmonary wedge pressure. The only index with a moderate correlation (r = 0.60) with the mitral diastolic gradient was that of Wells. The LVET/PEP index has only a mediocre correlation with the stroke volume (r = 0.50). The Oreshkov index was the only one among those studies to correlate at all significantly with the mitral valve area (r = --0.62). The investigation confirms the practical use of noninvasive methods in predicting the pulmonary wedge pressure, whilst the indices of Wells and Oreshkov seem less satisfactory in prediction both for the mitral diastolic gradient and the mitral valve area.