Heart Failure and Valvular Heart Disease

Chapter 27 Heart Failure and Valvular Heart Disease



Martin M. LeWinter, MD , Neil Agrawal, MD




1 What are the causes of cardiomyopathy resulting in the syndrome of heart failure (HF)?




image Reduced ejection fraction (HFREF, systolic HF, dilated cardiomyopathy): impaired contraction and/or loss of cardiomyocytes. Multiple causes but approximately 65% ischemic.


image Normal or preserved ejection fraction (HFNEF, diastolic HF): abnormal relaxation and/or increased stiffness of the left ventricle (LV), most commonly associated with hypertension, type 2 diabetes mellitus, and aging. Comorbidities (e.g., chronic obstructive pulmonary disease, stroke, obstructive sleep apnea) are very common.


image Restrictive cardiomyopathy: markedly decreased LV compliance leading to impaired diastolic filling. The usual cause is infiltrative disease.


image Hypertrophic cardiomyopathy: LV hypertrophy usually with asymmetric septal thickening and often outflow tract systolic pressure gradient. The mechanisms of HF are complex, but the presumed cause is sarcomeric protein mutations.


image Right ventricular (RV) failure: Most common causes are LV failure, obstructive sleep apnea, pulmonary hypertension, and RV myocardial infarction (MI).



2 What are the causes of HFREF besides ischemic heart disease or MI?


See Table 27-1.


Table 27-1 Causes of HFREF
























Type Cause
Myocarditis Infectious (viral) or inflammatory (e.g., systemic lupus erythematosus) giant cell (may require transplant)
Toxins EtOH, cocaine, cancer chemotherapy, radiation
Stress-induced cardiomyopathy Catecholamine surge from stress, apical ballooning (takotsubo syndrome)
Genetic Idiopathic, familial (multiple mutations)
Valvular disease Aortic, mitral (see valvular disease section)
Other Peripartum, sustained tachycardia, HTN, DM, endocrine or nutritional, acidosis, sepsis

DM, Diabetes mellitus; EtOH, ethyl alcohol; HTN, hypertension.



3 How do we classify HF by functional status or stage?


See Table 27-2.


Table 27-2 Classifying Heart Failure by Functional Status/Stage































NYHA Functional Classification
Class I (mild) No limitation of physical activity
Class II (mild) Slight limitation of physical activity
Class III (moderate) Marked limitation of physical activity
Class IV (severe) Unable to carry out any physical activity without discomfort, symptoms at rest
ACC-AHA Staging System
Stage A Patients at high risk for development of HF in the future but no functional or structural heart disease
Stage B Structural heart disease but no symptoms
Stage C Previous or current symptoms of HF in the context of underlying structural heart disease, adequately managed with medical treatment
Stage D Advanced disease requiring hospital-based support, heart transplantation or mechanical support, or palliative care

ACC, American College of Cardiology; AHA, American Heart Association; NYHA, New York Heart Association.



4 What is the role of brain natriuretic peptide in the diagnosis of HF?




image Not required to diagnose HF


image Helpful when diagnostic uncertainty exists and for prognosis


image Lower in HFNEF than in HFREF


image Lower in obese patients



5 How is acute decompensated HF treated?


Treatment is based on systemic perfusion and evidence of vascular congestion. See Table 27-3.



Table 27-3 Systemic Perfusion and Congestion

image

Congestion: dyspnea, orthopnea, crackles, elevated venous pressure, ascites, peripheral edema


Impaired perfusion: reduced pulse pressure, cold extremities, altered mentation


The numbers in Table 27-3 can be defined as follows:



1. Normal and requires no intervention.


2. Pump failure without pulmonary edema. Usually represents end-stage HF. Patients require inotropic support: dobutamine (β1-adrenergic agonist), milrinone (phosphodiesterase inhibitor), mechanical support (intraaortic balloon pump [IABP], LV assist device); consider cardiac transplantation.


3. Adequate perfusion with volume overload and increased filling pressures. The treatment focus is intravenous loop diuretics (most commonly furosemide) or bedside ultrafiltration. Reduction of preload with intravenous vasodilators (morphine sulfate, nitroglycerin or nitroprusside, angiotensin-converting enzyme inhibitors [ACEIs]) is another option.


4. Volume overload with pump failure. These patients require inotropes, vasodilators, diuretics, and consideration of mechanical support.


Notes:



image Ultrafiltration can remove large amounts of volume rapidly and is usually reserved for patients in whom an adequate response to IV diuretics is not achieved.


image Nesiritide is an alternative vasodilator therapy in patients whose blood pressure is normal and who continue to have dyspnea because of volume overload despite the use of intravenous loop diuretics.



6 How is diastolic dysfunction diagnosed?


An elevated LV end-diastolic or pulmonary capillary wedge pressure in a patient with a normal LV EF and end-diastolic volume by echocardiography establishes the presence of diastolic dysfunction. Various two-dimensional echocardiographic-Doppler parameters are also used, including increased ratio of early transmitral flow velocity to early diastolic velocity of the mitral valve annulus (E/E′), left atrial enlargement, and concentric LV hypertrophy.



Aortic stenosis



7 What are the causes of aortic stenosis (AS)?




image Supravalvular (rarest)


image Subvalvular (discrete, tunnel)


image Valvular


image Congenital


image Age 1 to 30 years, unicuspid


image Age 40 to 60 years, bicuspid


image Rheumatic


image Senile degenerative (> 70 years) → most common in United States

< div class='tao-gold-member'>

Related posts:

Poisoning by Cardiovascular Drugs Mechanical and Noninvasive Ventilation Alcohol Withdrawal Status Epilepticus Hemodynamic Monitoring Thyroid Disease in the Intensive Care Unit

Stay updated, free articles. Join our Telegram channel
Tags:
Jul 7, 2016 | Posted by in CRITICAL CARE | Comments Off on Heart Failure and Valvular Heart Disease

Full access? Get Clinical Tree
Get Clinical Tree app for offline access