Search

Myocarditis is an inflammatory disease of cardiac muscle with a variable clinical presentation, ranging from asymptomatic cases to different degrees of left ventricular systolic dysfunction up to heart failure and dilated heart disease. Ventricular arrhythmias (VA) can occur in patients with myocarditis and implantable cardioverter defibrillator (ICD) may be indicated in patients with life-threatening VA who are not in the acute phase of myocarditis and who are receiving optimal medical therapy. Reduced left ventricular ejection fraction (LVEF) below 35%, which is used as the main criterion for stratifying the risk of sudden cardiac death (SCD), has low sensitivity and low specificity for arrhythmic risk stratification in patients with myocarditis. Myocardial scar is the main determinant for VA in these patients. Cardiac magnetic resonance imaging (CMR), using late gadolinium enhancement(LGE), has an excellent ability to determinate the extension and characterization of myocardial scar, indeed CMR can potentially improve SCD risk stratification and indication for ICD implantation in patients with myocarditis. We present a case of a 36 years-old male presenting to the Emergency Department with a monomorphic sustained ventricular tachycardia in whom MRI revealed myocardial-pericardial recurrent inflammatory involvement and worsening disease progression. ICD was implanted in consideration of the high risk of life-threatening arrhythmias.

Atrial tachycardia and flutter frequently occur in association with atrial fibrillation and may be treated by overdrive pacing in patients who receive pacemakers with antitachycardia pacing (ATP) capabilities. The PITAGORA trial was a multi-centre, randomized, cross-over study aimed at comparing two different ATP modes for atrial tachyarrhythmia (AT) termination in patients suffering from sinus node disease (SND). METHODS AND RESULTS: One hundred and seventy-six patients (72 M, age 71+/-9 years) received a Medtronic AT500 pacemaker. All patients were on class IC or III antiarrhythmic drugs. After a 5-month observation period, 170 patients were randomized to either Ramp or Burst+ ATP therapy; 4 months later they crossed over. One hundred and fifty-seven patients completed the 13 months of follow-up; 114 (72.6%) suffered 6088 AT episodes. In 75 patients, 1904 AT episodes were treated and 934 (49.1%) successfully terminated. The median value of individual patients' ATP efficacy was 60%. Burst+ terminated 387 out of 873 AT episodes (44%) in 58 patients. Ramp terminated 547 out of 1031 AT episodes (53%, P240 ms. Quality of life, as measured by the EuroQoL questionnaire, and number of symptoms significantly improved in the overall population. This improvement was significantly higher in patients with ATP efficacy >60%. CONCLUSION: In patients suffering from SND and AT, Ramp therapy shows higher termination efficacy than Burst+ therapy in AT episodes with ATCL >240 ms. Further studies are required to show the impact of ATP on clinical outcomes.

BACKGROUND: Rhythm control is an important goal in the treatment of recurrent atrial tachyarrhythmias (AT). The PITAGORA study was a randomized trial in patients paced for sinus node disease (SND), designed to test the noninferiority of class IC antiarrhythmic drugs (AADs) to amiodarone in terms of a primary end point composed of death, permanent AT, cardiovascular hospitalization, atrial cardioversion, or AAD change. METHODS: Randomization was stratified to assign 2 patients to amiodarone and 2 patients to class IC AADs: propafenone or flecainide. One hundred seventy-six patients (46% men, 72 +/- 8 years) were enrolled. Device diagnostics continuously monitored AT recurrences and duration. RESULTS: In a mean follow-up of 20 +/- 9 months, the primary end point occurred in 23 (30.7%) of 75 class IC patients and in 28 (40.0%) of 70 amiodarone patients. The absolute difference in the end point incidence (-9.3%; 95% CI between 3.7% and -22.3%) confirmed the noninferiority of class IC to amiodarone (P = .007). Kaplan-Meier 1-year freedom from AT episodes >10 minutes, 1 day, and 7 days was 40%, 73%, and 91% for amiodarone and 28%, 78%, and 86% for class IC AADs (P = nonsignificant). CONCLUSIONS: In patients paced for SND and suffering from AT, class IC AADs proved not to be inferior to amiodarone in terms of the primary composite end point described or end points which were differently composed of mortality, efficacy, or AAD side effects. The AADs studied also showed similar results in terms of symptoms, quality of life, and freedom from AT recurrences.