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The Beta-blocker Strategy plus Implantable Cardioverter Defibrillator (BEST-ICD) Trial is a multicenter prospective randomized trial that started in June 1998, in 95 centers in Italy and Germany. The trial will test the hypothesis whether, in high-risk post myocardial infarction (MI) patients already treated with beta blockers, electrophysiologic study (EPS)-guided therapy (including the prophylactic implantation of implantable cardioverter defibrillator [ICD] in inducible patients) will improve survival compared with conventional therapy. Patients eligible for the study are survivors of recent MI (> or = 5 and < or = 21 days), aged < or = 80 years, with left ventricular ejection fraction < or = 35% and > or = 1 of the following additional risk factors: (1) ventricular premature beats > or = 10/hour; (2) decreased heart rate variability (standard deviation of unusual RR intervals < 70 msec); and (3) presence of ventricular late potentials. Furthermore, all enrolled patients must be able to tolerate at least 25 mg of metoprolol per day. These patients constitute about 9% of all patients with recent MI and are expected to have a 2-year all-cause mortality > 25% of which 50% is anticipated to be from sudden death. The main criteria of exclusion from the study are (1) a history of sustained ventricular arrhythmia; (2) documentation of nonsustained ventricular tachycardia during the screening phase; and (3) the need for myocardial revascularization and contraindications or intolerance to beta-blocker therapy. Eligible patients will be randomized to 2 different therapeutic strategies: conventional strategy or EPS/ICD strategy. Patients allocated to the EPS/ICD strategy will undergo further risk stratification, and electrophysiologically inducible patients (approximately 35%) will receive prophylactic ICDs, in addition to the conventional therapy, whereas noninducible patients will be only conventionally treated. The primary endpoint of the study will be death from all causes. By hypothesizing a 30% reduction in the 2-year mortality (from 20% to 14%) in the EPS/ICD group compared with conventionally treated patients, 1,200 patients will have to be included. A triangular, 2-sided sequential design with preset boundaries, for a 5% significance level and 90% power to detect a reduction in 2-year mortality from 20% to 14%, will be used to permit early termination of the trial if the strategy is found to be efficacious, no difference, or inefficacious. [ABSTRACT FROM AUTHOR]

Background: Modern pacemakers continuously store significant cardiac-related events. Interpreting these data and reprogramming the pacemaker can be time-consuming and demands expert knowledge. A software-based expert system, the therapy advisor (TA), was developed, which analyzes stored data and provides reprogramming recommendations. This study addresses whether pacemaker experts consider the messages that are automatically generated appropriate in the management of atrial tachyarrhythmias/atrial fibrillation (AT/AF)., Methods: This observational, international, multicenter study follows 150 patients with suspected or documented atrial arrhythmias who received a dual-chamber pacemaker (model Vitatron T-70, Medtronic Inc., Minneapolis, MN, USA) incorporating the TA. The TA summarizes technical and clinical data stored in the pacemaker into key messages and may suggest programming changes. Twenty-five cardiologists examined their patients per normal practice during two follow-up visits. They reported the therapy changes they deemed necessary without initially reviewing the TA messages. Next, they rated their satisfaction with and the clinical relevance of the TA messages and recorded the final therapy changes., Results: The TA generated (mostly AT/AF-related) main observations in 49% and programming advice in 33% of the patients. The experts rated 95% of the TA messages as satisfactory and deemed therapy changes necessary in roughly half the patients. Pacemaker changes in AT/AF therapy or general settings were prompted primarily by the diagnostic information stored in the device. Medication changes were mostly led by the symptoms reported by the patient., Conclusion: This study demonstrates that experienced cardiologists agree with 95% of the observations and programming suggestions that the TA automatically generates.

Background: The atrial Fibrillation/flutter Italian REgistry (FIRE) study was designed to obtain updated information regarding the clinical characteristics of and medical approach to patients requiring urgent medical care for atrial fibrillation (AF) or atrial flutter in a nationwide and representative series of hospitals., Methods: 4570 consecutive patients admitted to the emergency room for AF/atrial flutter were enrolled in 207 hospitals. Of these, 2838 (61.9%) were hospitalized (median 6 days, 43% in cardiology and 57% in internal medicine departments), and constitute the population of this study., Results: AF/atrial flutter represented 1.5% of all emergency room admissions and 3.3% of all hospitalizations. The mean age was 70 +/- 12 years; 89.9% had AF and 10.1% atrial flutter. In 31% of the hospitalized patients no cardiac disease was present, and in 18% no disease (either cardiac or non-cardiac) could be detected. Predictors of no attempt of cardioversion (37.5% of patients) included: onset of AF > 48 hours, heart failure, increasing age, syncope, admission to a non-cardiology department, stroke or transient ischemic attack (TIA). Predictors of in-hospital mortality (2.2%) included: age, heart failure, diabetes, admission to a non-cardiology department, and stroke or TIA. Predictors of the absence of sinus rhythm at discharge (35.6% of patients) included: no attempt of cardioversion, heart failure, chronic anticoagulation, AF duration > 48 hours, increasing age, stroke or TIA, and admission to a non-cardiology department. Transesophageal echocardiography was performed in only 6% of patients., Conclusions: AF/atrial flutter represent a significant burden on the health care system with a higher than expected hospitalization rate from the emergency room. One out of three discharged patients is not in sinus rhythm. There is still a wide gap between evidence-based medicine and real practice in the treatment of patients with AF.

Morphology Discrimination (MD) is a rhythm discriminator based on QRS morphology analysis that can be combined with other discriminators like Stability, with or without Sinus Interval History (SIH) and Sudden Onset. Thirty-five patients implanted with a St. Jude Medical single chamber ICD were evaluated during exercise testing, during induced AF, and during follow-up for 14 +/- 5 months. At exercise testing (60 episodes detected) MD had a specificity (SP) of 96.7% and Sudden Onset a SP of 91.7%; during induced AF (25 episodes) both MD and Stability had a SP of 96.0%. The diagnostic performance on spontaneous arrhythmias was as follows: for ventricular tachycardia (126 episodes) a sensitivity (SE) of 94.4% for MD, 92.1% for Sudden Onset, 89.7% for Stability without SIH and 79.4% for Stability + SIH; for sinus tachycardia (44 episodes) a SP of 86.4% for MD, 97.7% for Sudden Onset, 2.3% for Stability and of 95.5% for Stability + SIH. For AF (165 cases) a SP of 67.9% for MD, 69.1% for Stability and 90.3% for Stability + SIH, 44.8% for Sudden Onset. Use of MD alone provided a SE of 94.4% and a SP of 71.4% for spontaneous arrhythmias and combined use of the discriminators in a "2 of 3" diagnostic logic implied a SP of 90.9% with maintenance of 96.0% of SE. In single chamber ICDs a wide range of SE/SP ratios may be obtained by use of multiple discriminators, but use of the algorithm in a 2 of 3 diagnostic logic may achieve a SP of 90.9% and a SE of 96.0%.

Sepsis is still one of the most important causes of mortality and morbidity in the neonatal period. Infection is responsible for approximately 2 million neonatal deaths per year in developing countries. In Italy, as in other industrialized countries, the mortality rate has declined to 5.1 per 1000 livebirths. Progress in obstetrics and neonatal intensive care competence have improved survival particularly of preterm and low birth weight neonates. These neonates, for the immunological state and the invasive therapies they are subjected to, are extremely at risk for sepsis. Knowledge of neonatal risk factors, together with cytokines evaluation as early markers of sepsis and laboratory tests such as polymerase chain reaction, have allowed us to accelerate the diagnosis of sepsis with prognostic improvements. The frequent involvement of group B streptococci and coagulase-negative staphylococci requires empiric antibiotic therapy, effective for these pathogens, in all infants with suspected infection, waiting for blood cultures and antibiotic susceptibility results. Breast milk, carrier of immunologically active agents, is still the best prophylaxis for neonatal sepsis.

AutoCapture is a programmable feature of the Pacesetter Microny SR + 2425T VVIR pacemaker, which provides for the automatic capture verification, increase in output in the presence of noncapture and threshold searching, with adjustment of output settings. The effectiveness of this unit in conjunction with the Membrane models 1400T and 1401T bipolar endocardial leads was studied in 54 patients followed at 19 Italian Centers. The patients were randomized at the time of implantation to receive either the model 1400T or the 1401T lead. The electrodes in these leads are covered by a Nafion membrane, which was either impregnated (model 1400T) or not-impregnated (model 1401T) with steroid. This paper reports the data collected over the first six weeks postimplantation. The results of the automatic capture function was compared to the capture threshold measured using the Vario technique at the time of predischarge evaluations, and weeks 1,2, and 6 of postimplant follow-up. The reliability and effectiveness of the pulse generator-lead system allowed for consistent pacing at very low outputs and safety preserved at a programmed output only 0.3 V above the capture threshold.

Background: Synchronized direct current cardioversion (DC) is widely used for atrial fibrillation (AF) conversion to sinus rhythm. With the purpose to identificate the optimal procedure for the effective DC of AF, we compared the results obtained following traditional free-multiple shock sequence to simple two-shock sequence in two groups of adults with underlying heart disease submitted to elective DC for AF in our Dept. of Cardiology., Methods: The first group, retrospectively considered, included 84 episodes of AF occurred in 79 patients. DC started on an energy level of 100 joules (J) and, when unsuccessful, repeated on increasing levels, from 150J to 360J, depending on physician preference. An additional shock of 360J was always delivered when the last shock-dose proved to be ineffective. The second group, prospectively considered, included 61 episodes of AF occurred in 61 patients. The protocol provided for an initial shock of 200J followed, when necessary, by a second one of 360J and no additional shocks., Results: Conversion rate (86.9% vs. 85.2%) showed no statistical difference (p = NS) between groups. Following the two-shock protocol, a significant reduction of the mean amount of energy used for effective conversion (258.5J vs. 345.0J; p < 0.001), of the mean amount of total energy delivered to patients (302.9J vs. 439.6J; p < 0.001), particularly to non responders (560.0J vs. 1067.2J; p < 0.0001) was found. Using the first procedure only 13.1% of patients were cardioverted delivering 100J and 35.8% of them needed additional 200J. In the second group, the initial shock of 200J cardioverted 54.1% of patients. In both studies no patients had adverse effects either during or early after DC or during the four-week follow-up, where haemorrhagic and thromboembolic complications has been also considered., Conclusions: Two-shock protocol seems to provide better success/total energy delivered ratio, to reduce the total amount of energy delivered to each patient and to shorten the DC procedure when compared to free-multiple shock sequence usually performed, reducing the total time of anesthesia.

The increasing sophistication of implantable pacemakers for treating both tachycardia and bradycardia has resulted in the ability to use the implanted device for more interventions other than simple pacing. The interruption of tachyarrhythmias has been attempted using special programmers which allow stimulation at different cycle lengths, even very short ones. We describe two cases in which neither antitachycardia device nor special equipment were used to terminate an atrial flutter. Two patients with Sick Sinus syndrome who had received DDD pacemaker, presented with a sustained atrial flutter. Pacers were set in AOO mode at the highest rate programmable (119 and 130 ppm, respectively) obtaining an underdrive atrial pacing (F-F rate was 280 ppm in both cases) which was able to convert the atrial flutter to sinus rhythm. The procedure was performed in the outpatient clinic. Our cases illustrate one of many potential applications of permanent pacemakers in noninvasive settings. We can conclude that when atrial flutter occurs in AAI or DDD pacemaker recipients, underdrive atrial pacing using the implanted pacemaker should always be attempted.

Pacemaker mediated tachycardias (PMTs) are a well known complication of P synchronous pacing. Although the initiating mechanisms are several, all of them are associated with retrograde atrial activation, which is sensed by the atrial sensing channel, resulting in ventricular pacing. In 19 patients suffering from symptomatic AV conduction disturbances and normal sinus node function, a VDD pacing system connected to a single pass ventricular lead with dual chamber electrodes was implanted. The bipolar atrial electrode, floating in the right atrium, was used to detect endocardial atrial electrograms that were differentially processed within the pacemaker for optimal discrimination and filtering of undesirable signals. The widely programmable atrial sensitivity (amplitude and filtering) allowed stable P synchronized ventricular pacing in all patients, but in five of them, sustained PMTs not related to retrograde atrial activation was documented during the follow-up. The common mechanism for the onset and maintenance of these PMTs was traced to the abnormal sensing of the terminal forces of ventricular activation and/or of the T wave. The possibility of interferences between ventricular and atrial electrodes (crosstalk) was also considered. The reduction of atrial channel sensitivity represented in all cases the only effective procedure to prevent this type of PMT. In conclusion, the bet signal to noise ratio is an important endpoint to assure the proper function of a single lead VDD pacing system. Furthermore, using the differential amplifier built within the pacemaker, consideration should be given to the optimal mode of rejection of the terminal forces of the QRS and T wave.

Transesophageal atrial overdrive stimulation is a widely used technique for the interruption of atrial flutter and supraventricular tachyarrhythmias. We describe a case of 60 year old man with a previous myocardial infarction, suffering from angina during effort after aortocoronary bypass who presented several episodes of atrial flutter treated with success by transesophageal atrial overdrive stimulation using swallowing electrodes. During the treatment of the last episode of atrial flutter, after a 5 s burst at 300 b/min ventricular fibrillation occurred and was promptly interrupted by DC shock. This is the first case in our experience and probably the first report of ventricular fibrillation induced by swallowing electrodes. Possible mechanisms as pharmacological interactions, accidental ventricular stimulation, etc, are discussed. In conclusion, even though the risk of dangerous arrhythmias is very low, transesophageal atrial overdrive stimulation should be performed by experts in an equipped room.

The rate adaptive TX* pacemaker uses the evoked QT interval as an indicator of physiological demand. In order to obtain a rate adaptation close to physiological patterns we used in the past, in each patient, on the slope value and/or the T wave sensing window, controlling via exercise stress testing and Holter the results achieved. It was an expensive method, but the system produced effective rate responsive pacing. The new series of TX* pacemakers (Quintech 919 and Rhythmyx), beside the dynamic slope feature, are equipped with a 1-hour heart rate Holter (HRH) that can be used during effort without the need for manually recording the heart rate. In this mode TX* pacemakers calculate the average heart rate over 20-second periods and stores the values continuously for 1 hour. In addition, a 24-hour HRH is available, which calculates the average heart rate over 7.5-minute periods, showing heart rate trend during the last day prior to interrogation. Each HRH can be accessed by the programmer and printed out. Using four Quintech 919* and five Rhythmyx units, the inbuilt HRH proved its utility by making the heart rate adaptation checking procedure easier, faster, and more economic.

This report describes a case of Wolff-Parkinson-White syndrome with atrial fibrillation in which the ventricular complexes conducted over the accessory pathway have promptly disappeared with the use of intravenously administered lidocaine. Lidocaine is suggested as the most suitable drug in such situations. Finally possible connections are presented between high dosage administered lidocaine and conversion to normal sinus rhythm.

The diagnosis of Left Posterior Fascicular Block based on clinical ECG and VCG tracings alone is possible when ECG and VCG allow to recognize asynchronous left ventricular activation. The delayed inscription time of the intrinsecoid deflection in aVF (or V6) in absolute and relative to aVL permits the diagnosis if intrinsecond deflection in aVL exceeds 0,035". Il more premature, a further control is required to distinguish Left Ventricular Hypertrophy from Left Posterior Fascicular Block, both in anatomically vertical heart.