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The short-term prognosis of advanced refractory heart failure is extremely poor and closely correlated with progressive left ventricular dysfunction. The identification of the negative effects of conduction delay on cardiac performance, observed in almost 50% of heart failure patients, disclosed a new research field addressing the correction of electrical abnormalities in order to achieve an improvement in myocardial function. Biventricular stimulation, or cardiac resynchronization therapy, corrects the atrioventricular, inter- and intraventricular mechanical asynchrony and, to date, is indicated (class IIA, level of evidence A) for patients with NYHA class III-IV refractory heart failure regardless of its etiology, QRS interval > or = 130 ms, left ventricular end-diastolic diameter > or = 55 mm, and ejection fraction < or = 35%. To date, the completed trials demonstrated in patients undergoing biventricular pacing a significant improvement in left ventricular performance, quality of life and NYHA class with no significant effects on total mortality. The identification of non-responders (approximately 20-30% of the patient population in completed trials) represents an unresolved issue of cardiac resynchronization therapy. Tissue Doppler imaging evaluation of left ventricular dyssynchrony, which is being addressed by non-randomized prospective studies, should drastically decrease the percentage of these patients.

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.

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.

Pure acute Pandysautonomia (PAP), first described in 1969 by Young, is a rare but well defined clinical entity, in which the isolate involvement of Autonomic Nervous System (ANS) gives rise to a characteristic clinical admixture of symptoms and signs all due to the alteration of parasympathetic and sympathetic control of neurovegetative functions. The most prominent clinical features are: 1) postural hypotension without changes in heart rate leading to orthostatic syncopal or near-syncopal episodes, 2) abnormalities of intestinal tract and urinary bladder motility, leading to constipation alternating with diarrhea and urinary retention, 3) loss of sweating, 4) ocular abnormalities. We report a case of a 17 year old man with PAP, in whom almost complete resolution of clinical symptoms and signs of ANS involvement was observed within 9 months from the onset of illness. In our case, besides an accurate clinical and laboratory follow-up, particular attention was paid to investigate the cardiac responses to autonomic reflex tests and pharmacological interventions (atropine and beta-blocking drugs administration) during the entire course of illness. During the acute phase, complete vagal and almost complete beta-sympathetic "denervation" of the heart leading to disabling postural hypotension, fixed resting tachycardia and total unresponsiveness to Valsalva manoeuvre, were observed. PAP is a rare condition which must be known from cardiologists for a more complete knowledge of the etiology and pathophysiological mechanisms of postural syncopal attacks and must be distinguished from the less favourable progressive autonomic failure of the Shy-Drager syndrome.