Tiziano Toselli

Italian Multicenter Study on a Single Lead VDD Pacing System Using a Narrow Atrial Dipole Spacing

Since November 1988, 514 patients with advanced atrioventricular (AV) block and normal sinoatrial function have received the single lead VDD pacing system Twinal 30 Lem/CCS in 30 Italian centers. At implantation, particular attention was paid to the correct positioning of the atrial dipole in the mid‐ to mid‐high right atrium and to the atrial electrogram characteristics. The follow‐up included a chest X ray, to be performed before discharge of the patient from the hospital, telemetric evaluations of the endoatrial potential, provocative tests for interferences by myopotentials, 24‐hour ambulatory EGG recordings, and where possible, exercise stress tests. The mean follow‐up duration was 15.2 months, ranging from 1 to 42 months. A very low percentage of chronic atrial fibrillation, loss of atrial sensing, and system replacement was reported, most of the patients (93.5%) being paced in VDD mode. All investigations indicated an excellent overall system performance, stable AV synchrony, and infrequent myopotential interference, and a low complication rate throughout the follow‐up period.

Neurohormones and inflammatory mediators in patients with heart failure undergoing cardiac resynchronization therapy: time courses and prediction of response.

Despite interest in neurohormonal activation as a determinant of prognosis in chronic heart failure (CHF) and as a target for pharmacological treatments, data are lacking on the time-related effects of electrical cardiac resynchronization therapy (CRT) on a broad spectrum of neurohormones and cytokines. The aim of this study was to assess time-courses and extents of changes within the neurohormonal profile of CHF patients treated with CRT. We performed a prospective follow-up study in 32 patients with NYHA class III-IV CHF to investigate the effects of CRT on a broad panel of neurohormones proposed for characterization of CHF patients. Levels of atrial and brain natriuretic peptides (ANP, BNP), epinephrine, norepinephrine, aldosterone, plasma renin activity, IL-6, TNF, soluble receptors sTNFR1 and 2, and chromogranin A were assessed before implantation and after 3 months of CRT; when feasible, measurements were also performed at 1 week, 1 month and 12 months (clinical evaluation, echocardiography and ECG were also performed at each time-point). The results showed that at 3 months improvement in NYHA class and echographically assessed left ventricular (LV) reverse structural remodeling were accompanied by significant reductions versus baseline in ANP and BNP, but not in other neurohormones. Moreover a baseline ANP concentration < or = 150 pg/ml was a good predictor of response to CRT in terms of NYHA class reduction and reverse LV remodeling. In conclusion 3 months of CRT significantly reduce natriuretic peptides concentrations, while values of other neurohormones and inflammatory cytokines are relatively unvaried. A baseline ANP concentration < or = 150 pg/ml might be a clinically useful predictor of medium-term response to CRT.

Long‐Term Reliability of Single Lead Atrial Synchronous Pacing Systems Using Closely Spaced Atrial Dipoles: Five‐Year Experience

To assess the long‐term capability of single atrioven ticular (AV) lead VDD pacing systems using close atrial dipoles to assure reliable atrial guided pacing, the safety and efficacy of 86 VDD units implanted in 73 patients at a single center since November 1988 was reviewed. All patients suffered from advanced AV block with normal sinoatrial function. Sixty five patients received a LEM/CCS Twinal 30/30S system, four patients received a Vitatron‐Saphir system, and four patients received a Medtronic Thera VDR 8348 system. All patients underwent provocative tests in search of myopotential interference, and Holter recordings; in a group of patients who underwent pacemaker replacement a comparison was made between implant and replacement measurements. The mean follow‐up duration was 27.3 months. A high percentage of successfully VDD paced patients and a low incidence of pacemaker malfunction, regularly solved by pacemaker reprogramming, was reported. Atrial signal amplitudes comparable to those measured at implant were found at replacement in all patients. These data support the long‐term reliability of single AV lead VDD pacing systems with closely spaced atrial dipoles, as well as stable atrial sensing by floating bipolar atrial electrodes and effective atrial synchronous ventricular pacing over time.

Atrial septal aneurysm: Echopolycardiographic study

Atrial septal aneurysm (ASA) with diagnosis during life is a rarely reported anomaly, especially when not associated with other congenital or acquired valvular cardiopathies. Among 4,000 routine echocardiograms, 23 cases of ASA were found (8 men and 14 women, aged 19 to 79 years). Three patients had coronary artery disease, 2 had dilated cardiomyopathy, 2 had systemic hypertension, 11 had mitral valve prolapse and 5 had no other identifiable cardiovascular diseases. Echocardiography revealed various motion patterns of ASA. No phonomechanocardiographic findings were related to the presence of ASA, and no correlation between echographic and phonocardiographic findings was found.

AV delay optimization and management of DDD paced patients with dilated cardiomyopathy.

Ten DDD paced patients, suffering front dilated cardiomyopathy in the NYHA functional classes III or IV were studied by means of Doppler ecbocardiography at different programmed values of atrioventricular (AV) delay (200, 150, 120, 100, and 80 msec). The following variables were evaluated: LV diameter, ejection fraction, mitral and aortic flow velocity integrals, and stroke volume. During VDD pacing, a resting AV delay associated with the best diastolic filling and systolic function was identified and programmed individually. Shortening of the AV delay to about 100 msec was associated with a gradual and progressive improvement. Further decrease caused an impairment of systolic function. The patients were clinically and beinodynamically reevaluated after 2 months of follow‐up. A reduction of NYHA class and an improvement of LV function were consistently found. The reported data suggest that programming of an optimal A V delay may improve myocardial function in DDD paced patients with congestive heart failure. This result may be the consequence of an optimization of left ventricular filling and a better use of the Frank‐Starling law.

Cardiac resynchronization therapy guided by multimodality cardiac imaging

Up to 30–45% of implanted patients are non‐responders to CRT. We evaluated the role of a ‘CRT team’ using cardiac magnetic resonance (CMR) and longitudinal myocardial strain to identify the target area defined as the most delayed and viable region for LV pacing.

Comparison of myocardial deformation and velocity dyssynchrony for identification of responders to cardiac resynchronization therapy

It is unclear whether myocardial velocity or deformation indices of dyssynchrony are better at predicting response to cardiac resynchronization therapy (CRT). Therefore, two indices of left ventricular (LV) dyssynchrony based on myocardial velocity and deformation were compared to predict success of CRT.

A New Single Lead VDD Pacing System

PERCOCO, G.F., ET AL.: A New Single Lead VDD Pacing System. In 24 patients with advanced heart block and normal sinus node function, a new single lead VDD pacing system was implanted. At implantation, the endoatrial, bipolar electrogram was recorded in all patients. The lead position was checked by means of chest X‐ray. At discharge and after 1, 3, and 6 months, testing for myopotential inhibition, telemetric evaluation of the endoatrial potential, and Holter recordings were made. After discharge, 18 patients performed two cardiopulmonary exercise tests at two different rate‐matched AV intervals. All investigations showed good AV synchrony and a lack of interferences by myopotentials. The maximum rate‐matched AV interval provided a significantly improved exercise capacity, which was more evident in patients with signs of myocardial failure.

Cardiac device therapy in patients with left ventricular dysfunction and heart failure: 'real-world' data on long-term outcomes (mortality, hospitalizations, days alive and out of hospital).

The impact on long‐term outcomes of implantable cardioverter defibrillators (ICDs) and biventricular defibrillators for cardiac resynchronization (CRT‐D) devices in ‘real world’ patients with heart failure (HF) needs to be assessed in terms of clinical effectiveness.

Atrial Fibrillation and Recurrent Ventricular Fibrillation During Hypokalemia in Brugada Syndrome

A 41‐year‐old man with Brugada syndrome (BS) and no previous episodes of aborted sudden death or syncope referred to local emergency room for an episode of symptomatic atrial fibrillation. Blood chemistry results showed hypokalemia (2.9 mEq/L). The other parameters were within the normal range. After few minutes, an episode of ventricular fibrillation treated with biphasic DC shock 150 J occurred. In successive 2 hours, the patient experienced recurrent episodes of ventricular tachycardia and fibrillation. Each biphasic DC shock 150 J was effective to restore sinus rhythm. No further episodes occurred after normalization of serum levels of potassium. Before discharge, an implantable cardioverter defibrillator was inserted to prevent sudden cardiac death. Hypokalemia increases the risk of arrhythmic events in BS.