[The long-term effects of dual-chamber stimulation in 8 patients with hypertrophic obstructive cardiomyopathy and symptoms refractory to medical therapy]. / Effetti a lungo termine della stimolazione bicamerale in otto pazienti portatori di cardiomiopatia ipertrofica ostruttiva con sintomi refrattari a terapia medica.

BACKGROUND: The issue of DDD pacing as a therapeutic option for patients with obstructive hypertrophic cardiomyopathy is still under debate. Moreover, some authors stress the concept of the placebo effect of electrical therapy in this particular setting. METHODS: We retrospectively evaluated 8 symptomatic patients with obstructive hypertrophic cardiomyopathy despite medical therapy, who underwent DDD pacemaker implantation as an adjunctive therapeutic strategy. All patients were evaluated with a two-dimensional/Doppler echocardiogram at baseline, shortly after the beginning of DDD pacing and at follow-up. In 3 patients dobutamine stimulation was necessary to elicit the intraventricular gradient. RESULTS: At follow-up (21 +/- 19 months, range 1-54 months) the peak gradient declined from 86 +/- 27 to 34 +/- 27 mmHg (55.2%). In 4 patients the peak gradient sharply declined after pacemaker implantation with active pacing and remained stable throughout the follow-up. In 2 patients we noted a continuous reduction in the peak gradient during the follow-up, while in 2 patients it returned to baseline values after 1 year and 1 month, respectively, despite an early reduction with DDD pacing. All patients experienced symptomatic amelioration throughout the follow-up. Two patients developed angina at the end of our observation together with an increase in the peak gradient. CONCLUSIONS: We believe that DDD pacing may be considered as a practical therapeutic option for patients with obstructive hypertrophic cardiomyopathy who would otherwise be regarded as candidates for surgery.

[Long-term clinical assessment of single-lead VDD electric stimulation]. / Valutazione clinica a lungo termine dell'elettrostimolazione VDD monocatetere.

BACKGROUND: During the last decade single lead VDD pacing has been progressively affirmed as an electrotherapy of choice in patients with advanced atrioventricular block without alterations of the sinus function. It combines the benefits of P-synchronous ventricular pacing with an easy implant procedure when compared to the conventional DDD approach. The aim of this study was to evaluate the validity of such an approach in a large population of patients, all implanted in a single center. METHODS: From 1987 up to now, 317 patients, all affected by advanced atrioventricular block and without sinus node dysfunction, were implanted in our center with a single lead VDD pacemaker. During follow-up the persistence of a proper atrioventricular synchronization was assessed and evaluated. RESULTS: The mean follow-up was 3.9 +/- 2.7 years/patient (range 6-138 months). The 94.6% of implanted systems maintained the normal VDD pacing function. Permanent reprogramming in VVI mode was necessary in 17 patients (5.36%); in 12 (3.78%) because of chronic atrial fibrillation and in 5 (1.63%) for loss of atrial sensing. The percentage of atrial synchronization was optimal (> 98%) and acceptable (> 95%) in 81% and 19% of patients, respectively. Episodes of paroxysmal atrial fibrillation occurred in 3 patients. Neither inhibition by myopotentials nor occurrence of sinus node disease was observed during follow-up. These results are in accordance with those reported by previous studies, performed on a smaller population or on a multicenter basis, and are comparable with the results reported for conventional DDD pacemaker. CONCLUSIONS: Our results confirm the high reliability of the single lead VDD pacing system concerning the long-term persistence of a proper atrioventricular synchronization. Data showed above enforce our opinion that this pacing approach should be considered the treatment of choice in patients with advanced atrioventricular block and preserved sinus node function.

Comparison of coronary angiographic narrowing in stable angina pectoris, unstable angina pectoris, and in acute myocardial infarction.

Coronary angiographic findings were compared in patients who presented with acute myocardial infarction (AMI, n = 75), unstable angina pectoris (UAP, n = 36), or stable angina pectoris (SAP, n = 36) for > or = 2 years without evidence of any previous acute event and with an angiogram within 2 years of the initial symptoms. Angiograms were evaluated blindly for severity, extent (depending on the percentage of each coronary segment showing atherosclerosis), and pattern (discrete, < 3 loci of narrowings involving < 50% of any segment; diffuse, anything exceeding this). Patients in the SAP group had more narrowed arteries (2.4 +/- 0.7 vs 1.3 +/- 0.6 [p < 0.02] and 1.4 +/- 0.6 [p < 0.02]), more stenoses (6.0 +/- 3.3 vs 2.1 +/- 1.5 [p < 0.01] and 2.6 +/- 1.7 [p < 0.05]) and occlusions (1.3 +/- 1.1 vs 0.7 +/- 0.6 [p = 0.05] and 0.3 +/- 0.5 [p < 0.02]), and a greater extent index (0.9 +/- 0.5 vs 0.5 +/- 0.3 [p < 0.02] and 0.5 +/- 0.3 [p < 0.02]) than those in the AMI and UAP groups. Furthermore, a discrete pattern was less prevalent in patients with UAP than in those with SAP or AMI (3% vs 40% [p < 0.02] and 25% [p < 0.05], respectively). In conclusion, patients who present with acute coronary syndromes have less extensive atherosclerosis than those who present with chronic stable angina. Therefore, in the former group, coronary atherosclerosis appears to be more susceptible to ischemic stimuli responsible for acute coronary syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)

[Circadian rhythm of the heart rate and autonomic nervous system stimulation tests in patients with systemic lupus erythematosus]. / Ritmo circadiano della frequenza cardiaca e prove di stimolazione autonomica in pazienti con lupus eritematoso sistemico.

We studied 19 women (mean age 35 +/- 13 years) with systemic lupus erythematosus (SLE), in order to evaluate whether or not alterations in the circadian rhythm of heart rate (HR) occur in patients with pathologic responses to stimulation tests of the autonomic nervous system (ST-ANS). The duration of SLE was 5.3 +/- 5 years. None of the patients had clinical signs of cardiopathy or dysautonomy, nor were any of them taking drugs with known effects on the heart or ANS. Nine patients (47%, group A) had normal ST-ANS and 10 (53%, group B) had an abnormal response to at least 1 ST-ANS (5 to sympathetic ANS, 3 to parasympathetic and 2 to both ST-ANS). Age, duration of disease and therapy were not different between the 2 groups. All patients underwent 24-hour ambulatory ECG monitoring, and chronobiologic analysis of hourly HR was carried out by single and mean cosinor methods. A significant circadian rhythm was found both in the total sample (mesor 80 b/min, acrophase h 13:12; p less than 0.01), and, separately, in group A (mesor 82 b/min, acrophase h 13:11; p less than 0.01) and group B (mesor 78 b/min, acrophase h 13:12; p less than 0.01). No difference existed between the HR circadian rhythms of the 2 groups. Thus, our data show the possibility of ANS involvement in SLE patients without clinical signs of dysautonomy; the analysis of the HR circadian rhythm does not appear to be a sensitive method to identify early involvement of the ANS in these patients.

Reproducibility in circadian rhythm of ventricular premature complexes.

To evaluate the existence and reproducibility of a circadian rhythm of ventricular premature complexes (VPCs), 38 patients (mean age 57 +/- 17 years) with greater than or equal to VPCs/hour were studied with 24-hour electrocardiogram Holter monitoring. Nineteen patients had coronary artery disease and 19 had structurally normal hearts. A second Holter electrocardiogram was recorded in all patients from 2 to 47 days (mean 11) after the first. Chronobiologic analysis was made by single and mean cosinor methods. A significant and similar circadian rhythm of VPCs was found in the total sample both on the first (mesor 399, acrophase at 15:08, p less than 0.01) and the second day (mesor 306, acrophase at 14:47, p less than 0.05), with 2 main peaks, the first in the late morning and the second in the afternoon. However, only 18 patients (47%, group A) had a significant individual circadian rhythm of VPCs on both days, whereas 20 (53%, group B) did not have a significant rhythm in greater than or equal to 1 day. A high reproducibility of the circadian rhythm of VPCs was found in group A patients, with a difference of 2.1 +/- 1.8 hours between the acrophases of the 2 days, whereas the difference was 4.4 +/- 3.3 hours in group B patients (p less than 0.01). Among group A patients, 14 (78%) had a VPC rhythm with acrophase occurring during waking hours, whereas the acrophase of 4 (22%) occurred during the night. The reproducibility of the circadian rhythm of VPCs was not influenced by gender, presence of coronary disease, medical therapy, basal VPC number, or day-to-day variability of VPCs, although group A patients were older than group B patients (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Resumption of sinus rhythm during general anaesthesia in an elderly patient with chronic atrial fibrillation: a case report.

Conversion to sinus rhythm is a rare event in a patient with chronic atrial fibrillation. There are no reports in the literature of this happening during general anaesthesia. This case report presents such a case and discusses the possible aetiology.

Assessment of left atrial dimensions by cross sectional echocardiography in patients with mitral valve disease.

Left atrial dimensions were measured using cross sectional echocardiography in 37 patients with mitral valve disease and 30 normal subjects of similar ages. The anteroposterior (AP), superior-inferior (SI), and medial-lateral (ML) left atrial dimensions were determined at the end of ventricular systole using parasternal long and short axis and apical four chamber views (for SIa and MLa). To assess the reliability of these measurements cross sectional echocardiographic and angiographic left atrial volumes were compared in 19 patients with mitral valve disease, giving an excellent correlation. A moderate correlation was found between the anteroposterior dimension of the left atrium obtained using M mode echocardiography and that obtained using the parasternal short axis and long axis projections. In normal subjects a good correlation was found between SI and ML dimensions, while a lower correlation was found between SI and AP, and ML and AP dimensions. The SI dimension was the major axis of the left atrium and AP dimension the minor axis. In patients with mitral valve disease a good correlation was found between SI and ML dimensions, while SI and ML dimensions had a low correlation with AP dimensions. The AP dimension was the minor axis of the left atrium, while the SI and ML dimensions were not significantly different. All left atrial dimensions were significantly greater in patients with mitral valve disease than in normal subjects. Of 30 patients with at least one dimension increased, all three dimensions were abnormal in 16, two dimensions were increased in 10, and only one dimension was increased in four. AP, SI, and ML dimensions were abnormal in 25, 20, and 27 patients, respectively. Cross sectional echocardiography may provide a reliable estimate of left atrial dimensions. In patients with mitral valve disease a thorough examination of the left atrium using multiple cross sectional views is necessary to detect asymmetric left atrial enlargement and to measure the degree of left atrial dilatation.

Oral nifedipine in the long-term management of severe chronic heart failure.

We evaluated the hemodynamic effects of nifedipine in 10 symptomatic patients with chronic refractory heart failure due to idiopathic cardiomyopathy. Nifedipine significantly increased cardiac index (from 1.80 +/- 0.4 to 3 +/- 0.6 L/min/m2), stroke volume index (from 21 +/- 6 to 33 +/- 8 ml/beat/m2), and stroke work index (from 17.9 +/- 7 to 25.5 +/- 7 g-m/m2). The drugs also produced a significant decrease in left ventricular filling pressure (from 24.6 +/- 3 to 19 +/- 2 mm Hg), mean blood pressure (from 86 +/- 9 to 74 +/- 5 mm Hg), mean pulmonary arterial pressure (from 31.9 +/- 5 to 25.6 +/- 3 mm Hg), total systemic vascular resistance (from 2,104 +/- 329 to 1,088 +/- 249 dyn/s/cm-5), and pulmonary vascular resistance (from 200 +/- 71 to 107 +/- 50 dyn/s/cm-5). Heart rate remained unchanged. In all patients maintained on nifedipine therapy, repeat hemodynamic studies at 2 months revealed sustained effects, and all patients had symptomatic improvement of at least one New York Heart Association (NYHA) functional class. Long-term treatment was well tolerated. Forty-eight hours after discontinuation of nifedipine administration the hemodynamic benefits were lost. We conclude that nifedipine may be of value for long-term ambulatory therapy of severe chronic heart failure.

Beta-thromboglobulin in patients with acute and chronic coronary artery disease.

Beta-thromboglobulin (beta TG) plasma levels were measured by radioimmunoassay in 14 patients with acute myocardial infarction (MI), in 13 with myocardial ischemia and recurrent episodes of angina and in 14 subjects with a past history of MI. Increased beta TG plasma values were observed in patients with acute MI and with myocardial ischemia whereas subjects with a past history of MI showed results not significantly different from normal subjects. Daily measurements in acute MI showed in five cases a second peak of beta TG values which suggests the occurrence of a deep vein thrombosis. The increased platelet consumption in MI was not related with the extent of the necrosis. We suggest, therefore, that platelet activation is associated with myocardial ischemia rather than necrosis.

[Mexiletine in treatment of chronic ventricular refractary arrhythmias (author's transl)]. / La mexiletina nel trattamento delle aritmie ventricolari croniche refrattarie.

We studied the antiarrhythmic effect of oral Mexiletine in 20 patients with stable high-frequency ventricular arrhythmias refractory to therapeutic doses of conventional antiarrhythmic therapy. Arrhythmias were classified according to modified grading system of Lown and Wolf. The efficacy of Mexiletine was assessed with use of both the arrhythmic modified classification of Lown and Wolf and count of premature ventricular beats (PVB) from 24 hours ambulatory electrocardiographic recordings. The dose of Mexiletine was 300 mg every 8 hours; 24 hours ECG recordings were obtained in each patient on days 5,15 and 20 during Mexiletine therapy. The worst of tracings before and during Mexiletine therapy was compared. Mean decrease in PVB was 57% (P less than 0.001). The decrease in PVB was more than 80% in 11 patients. Comparison of the grade of arrhythmias disclosed a favorable effect of Mexiletine in 13 patients, a worsening in 1, and no effect in 6. Classification of the most severe arrhythmia revealed a significant decrease from an average grade of 3.05 to 1.75 (P less than 0.01). Before Mexiletine therapy, 40% of our patients were in Class 0 to II and 60% were in Class III or V, whereas during Mexiletine therapy the corresponding proportions were 75% and 25% respectively. Side effects (confusion, tremors, gastro-intestinal complaints) prompted reduction of the dose in 3 patients. Three additional patients had transient minor side effects (dizziness, nystagmus and gastrointestinal disorders) that did not necessitate a change in therapy and 14 patients reported no side effects. In conclusion our data suggest that Mexiletine is an effective agent in the long-term treatment of serious ventricular arrhythmias refractory to other agents. Since Mexiletine therapy is not associated with severe long-term side effects, it should now be possible to determine its role as a first-line drug for treating ventricular arrhythmias.

[The hemodynamic effects of nifedipine in congestive cardiomyopathy (author's transl)]. / Effetti emodinamici della nifedipina nella cardiomiopatia congestizia.

The Authors present the haemodynamic effects of nifedipina (Adalat-Bayer) in nine patients with congestive cardiomyopathy. Heart rate (HR), systemic vascular resistances (SVR) and mean aortic blood pressure (MABP) were significantly modified in all nine patients following the administration of the drug. Six of them showed an increase of cardiac index (CI) and a decrease of myocardial oxygen consumption (MVO2); three of them presented a decrease of CI and an increase of MVO2. This discrepancy can be due to the different percentage of increase and to the maximal of valves of HR in the two groups. Nifedipina can be useful in the treatment of congestive cardiomyopathy with elevated STR (afterload) and peripheral hypoperfusion (more than pulmonary congestion).

[Cardiac rupture: a not infrequent complication of acute myocardial infarction. Report of five cases (author's transl)]. / La rottura di cuore: una non rara complicanza dell'infarto miocardico acuto. Descrizione di 5 casi.

Five cases of cardiac rupture (CR) in acute myocardial infarction (AMI) (four men and one woman aged between 49 and 86 years, mean 64) are described. The incidence of CR was 4,7% of 106 cases of AMI and 20,8% of causes of death. In all cases, pathologic observations well agreed with electrocardiographic site of infarction. All patients had ECG pattern of transmural AMI: postero-inferior (2 cases), anterior (1 case); none of them had myocardial infarction in the past. Two patients had systolic hypertension on admission, during and immediately before death, and 3 patients were normotensive during the whole course of illness. All patients had severe, prolonged and resistant to opiate therapy chest pain, which reexacerbated immediately before death in two cases. 4 patients died within 24 hours after the onset of symptoms. Terminal ECG pattern was similar in these four cases: sudden sinus bradycardia and/or idio-ventricular rhythm, with a progressive slowing of heart rate and changes of QRS patterns of "agonic" type, preceded electrical activity cessation. In one patient, who died at the seventh day of illness, ventricular fibrillation was observed. The AA. stress the importance of the early recognition of clinical findings suggesting an impeding CR in order to relieve cardiac tamponade with pericardiocentesis and to perform, as soon as possible, surgical treatment.