Pulmonary Hypertension and Cardiac Resynchronization Therapy: Evaluation Prior to Implantation and Response to Therapy

History

The patient was referred from another center for consideration of cardiac resynchronization therapy (CRT) for long-standing ischemic cardiomyopathy and progressive heart failure symptoms. At time of referral he described New York Heart Association (NYHA) class III symptoms despite optimal medical therapy.

The patient’s history included ischemic heart disease, first diagnosed at 40 years of age. At that time he also had exertional angina. A 12-lead electrocardiogram (ECG) showed left bundle branch morphology. Echocardiography and left ventriculography demonstrated impaired left ventricular function with a left ventricular ejection fraction of 40%. Coronary angiography demonstrated severe three-vessel coronary artery disease. He underwent coronary bypass grafting at 40 years of age, with left internal mammary grafting to the left anterior descending artery and saphenous vein grafts to the lateral circumflex and posterior descending arteries. He then remained asymptomatic until ventricular fibrillation arrest occurred while driving in a car race at 50 years of age. Coronary bypass grafts were intact, with no new native coronary lesions suitable for percutaneous intervention. Left ventricular function remained mildly impaired. Treatment with amiodarone was initiated, and he underwent implantation of an implantable cardioverter-defibrillator at that time. He had no further ventricular arrhythmias or device therapies delivered, but over the ensuing 8 years he developed progressive symptoms of heart failure accompanied by a decline in left ventricular systolic function. At the time of referral for CRT, he had no symptoms of ischemic heart disease and coronary angiography demonstrated patent grafts but diffuse native coronary disease.

Apart from hyperlipidemia, the patient had no history of other significant medical conditions.

Current Medications

The patient was taking spironolactone 25 mg daily, furosemide 120 mg daily, atorvastatin 20 mg daily, carvedilol 12.5 mg twice daily, enalapril 5 mg twice daily, amiodarone 200 mg daily, and enteric coated aspirin 100 mg daily.

Current Symptoms

The patient experienced NYHA class III symptoms of shortness of breath and fatigue and occasional orthopnea and paroxysmal nocturnal dyspnea. He had no syncope, palpitations, or anginal symptoms.

Physical Examination

• BP/HR: 105/60 mm Hg/60 bpm

• Height/weight: 171 cm/77 kg

• Neck veins: +4 cm, hepatojugular reflux positive

• Lungs/chest: Resonant to percussion, vesicular breath sounds with bibasal fine, late-inspiratory crackles

• Heart: Laterally displaced, diffuse apex beat impulse, first heart sound (S ₁ ) + second heart sound (S ₂ ) + third heart sound (S ₃ ); grade 3 apical pan-systolic murmur radiating to the axilla

• Abdomen: No abnormality

• Extremities: No edema, normal volume pulses

Laboratory Data

• Hemoglobin: 12.6 mg/dL

• Hematocrit/packed cell volume: 39%

• Mean corpuscular volume: 91 fL

• Platelet count: 272 × 10 ³ /µL

• Sodium: 136 mmol/L

• Potassium: 4.3 mmol/L

• Creatinine: 1.58 mg/dL

• Blood urea nitrogen: 82 mg/dL

Electrocardiogram

Findings

The ECG in Figure 46-1 shows a sinus rhythm of 60 bpm, left bundle branch block, and QRS duration of 190 ms.

Echocardiogram

Findings

The echocardiogram showed severe left ventricular dilation with an end-diastolic volume of 484 mL, end-systolic volume of 380 mL, with severe global systolic dysfunction and calculated ejection fraction of 21% ( Figure 46-2 ).