 To assess the incidence of Sleep Apnea-Hypopnea Syndrome SAHS, both obstructive and central, in patients with: 1 pacemaker indication; 2 implantable cardioverter defibrillator ICD or cardiac resynchronization therapy CRTD, 3 heart failure and preserved left ventricular ejection fraction LVEF and 4 heart failure and reduced LVEF. 