Problems with ensuring patient examinations defined in the protocol of the study

The purpose of this study is further risk stratification of patients receiving implantable cardioverter-defibrillator in primary prevention of sudden cardiac death.

Current criteria for risk stratification of patients in risk of sudden cardiac death are mainly based on left ventricular ejection fraction and NYHA class. This criteria are too robust, approximately 2/3 of ICD recipients do not profit from this treatment in the following 5 years, especially those with non-ischaemic cardiomyopathy. We plan to sub-stratify this group of patients with both ischaemic and non-ischaemic cardiomyopathy by: non-linear heart rate variability analysis, microvolt T-wave alternans, QRT-T angle and character and amount of left ventricular scarring assessed by magnetic resonance imaging. Pre-implantation values will be correlated with numbers and character of ICD therapy (both anti-tachycardial pacing and ICD discharge). The results may allow to decrease the number of patients, who do not profit from ICD treatment.

Inclusion Criteria:

• LVD (left ventricular dysfunction) d/t MI (Myocardial infarction), LVEF 30% or less, NYHA (New York Heart association class) II, III
• LVD d/t MI, LVEF 30% to 35%, NYHA II, III
• LVD d/t MI, LVEF 30% to 40%, NSVT, positive EP study
• LVD d/t MI, LVEF 30% or less, NYHA I
• NICM (non-ischaemic cardiomyopathy), LVEF 30% or less, NYHA II, III
• NICM, LVEF 30% to 35%, NYHA II, III
• NICM, LVEF 30% or less, NYHA I
• signed informed consent

Exclusion Criteria:

• metallic foreign body (metal sliver) in their eye, or who have an aneurysm clip in their brain, cannot have an MRI scan since the magnetic field may dislodge the metal
• severe claustrophobia may not be able to tolerate an MRI scan
• heart rhythm device in place before enrollment
• atrial fibrillation in time of enrollment
• ICD implantation indicated from secondary prevention of SCD (sudden cardiac death)
• NYHA or CCS class IV
• PCI or CABG in last 3 months
• CMP/TIA in last 3 months
• syncope of unknown etiology

Heart-failure clinic,primary care clinic