A 63-year-old male smoker with type 2 diabetes presents for the first time with chest pain and shortness of breath at rest. He has no recent history of viral infection and no family history of heart failure or sudden cardiac death.<\/p>\n
Initial laboratory testing documents negative troponin, normal calcium, normal serum angiotensin-converting-enzyme (ACE) activity, and a negative HIV test. He has no hilar lymphadenopathy.<\/p>\n
After being managed with intravenous diuretics and stabilized with ramipril 1.25 mg once daily and furosemide 40 mg twice daily, the patient still has significant limitations and mobilizes comfortably only around the bed. His systolic blood pressure (about 95 mm Hg) prevents the introduction of a beta-blocker. His intermittently high potassium level (up to 6.1 mmol\/liter) precludes use of an aldosterone antagonist.<\/p>\n
Other Findings<\/span><\/p>\n Electrocardiogram: <\/i>left bundle-branch block, QRS duration 120 msec, and first-degree heart block (PR interval, 220 msec).<\/p>\n Echocardiogram: <\/i>dilated left ventricle (end-diastolic diameter, 5.8 cm); LV ejection fraction, using Simpson\u2019s biplane, of 16%; mildly dilated and significantly impaired right ventricle; elevated pulmonary artery pressure (about 50 mm Hg).<\/p>\n Coronary angiography:<\/i> normal coronary arteries<\/p>\n MRI:<\/i> no late gadolinium enhancement<\/p>\n Cardiac monitoring:<\/i> periodic 2:1 heart block (<10% of the time)<\/p>\n All of the clinicians who considered the patient\u2019s case agree that a device is warranted.<\/p>\n Which device should this patient receive as chronic therapy?<\/b><\/p>\n <\/b>1. Dual-chamber pacemaker.<\/i> The patient currently does not pace >40% of the time, and his expected progress is hard to determine. His device can be upgraded if he stabilizes in NYHA class III or better (although not according to current UK guidelines) and if optimal medication does not improve his left-ventricular function.<\/p>\n 2. Cardiac resynchronization therapy\u2013pacemaker (CRT-P) device.<\/i> The patient\u2019s ventricular function is poor and is unlikely to recover significantly. Furthermore, his conduction disease will progress, and he is likely to become dependent on pacing during the lifetime of the device. Given that he is arguably still in NYHA class IV, albeit ambulatory, he is currently not eligible for a defibrillator.<\/p>\n 3. CRT\u2013defibrillator (CRT-D) device. <\/i>The patient is improving and with good medical therapy is likely to improve further. He has very poor ventricular function, and his conduction disease raises the possibility of a laminopathy, further increasing his risk level.<\/p>\n 4. Another option<\/i><\/p>\n <\/p>\n Response:<\/b><\/p>\n