6.4 - Classification and Medical Management of Heart Failure

heart failure

can reflect either inability to empty adequately during systole or inability to fill adequately during diastole

• can arise from acute process (MI) or chronic process (HTN)

  • systolic failure → poor pumping

  • diastolic failure → poor filling from stenotic valve / stiff ventricle

• cardinal clinical findings include dyspnea and fatigue

• most patients have left and right heart failure

  • left heart failure determined by left ventricle ejection fraction

  • % blood ejected from left ventricle during systole

    • normal = 55-70%

    • threshold for failure = 45-50%

dyspnea from heart failure

dyspnea results from congested pulmonary tissues

• central regulation of respiration may become impaired

  • Cheyne-Stokes respirations → rapid, deep breathing alternating with apnea

AHA / ACC joint classification of heart failure

• stage A → high risk, but no structural heart disease and no symptoms

  • risk factor include HTN, IHD, obesity, smoking

• stage B → structural heart changes, but no symptoms

  • examples — LV hypertrophy, dilated ventricle

• stage C → structural heart disease + prior / current symptoms

  • NYHA classification by structural change and symptoms

    • class I — no limitation in physical activity and no symptoms

    • class II — symptoms with more activity

    • class III — symptoms with little activity

    • class IV — symptoms at rest

• stage D → refractory / end-stage heart failure requiring specialized interventions

  • may require transplant, mechanical support, experimental treatment, hospice / end-of-life care

medical management by stage

• stage A → high risk, but no structural heart disease and no symptoms

  • manage underlying diseases and risk factors

• stage B → structural heart changes, but no symptoms

  • manage underlying diseases and risk factors

• stage C → structural heart disease + prior / current symptoms

  • manage underlying diseases and risk factors

  • common medications include ACE inhibitors, diuretics, beta-blocker, aldosterone antagonists, ARBs, digitalis, hydralazine

  • devices in selected patients include biventricular spacing, implantable defibrillators

• stage D → refractory / end-stage heart failure requiring specialized interventions

  • manage underlying diseases and risk factors

  • common medications

  • heart transplant, other surgeries, experimental treatment, mechanical support, end-of-life care / hospice