by mtoom


keywords:
Bookmark and Share



Front Back
What is heart failure?
Clinical syndrome resulting from the heart's inability to meet the body's circulatory demands under normal physiological conditions.
In heart failure, some initial insult leads to reduced cardiac output. In terms of pathophysiology, this leads to the activation of what two mechanisms?
  • Renin angiotensin aldosterone system (RAAS) is activated
  • Sympathetic nervous system is activated
In heart failure, activation of RAAS and sympathetic nervous system leads to what effects on:
  • Vasculature
  • Volume 
  • System vasoconstriction
  • Volume retention
In heart failure, how do vasoconstriction and volume retention lead to pulmonary congestion?
  • ↑venous return leads to ↑preload
  • ↑preload (= LVEDP) transmits ↑pressure back to the pulmonary veins
How does preload affect the stroke volume in a normal heart versus in severe CHF?
Normally, ↑preload leads to ↑stroke volume (= greater contractility) but in severe CHF, the heart suffers from impaired contractility and so the stroke volume does not increase appropriately with ↑preload, but plateaus instead.
What are the two types of heart failure?
  • Systolic
  • Diastolic
What are the causes of systolic heart failure? (3)
  • Ischemic heart disease (specifically, myocardial infarction)
  • Hypertension → cardiomyopathy
  • Valvular heart disease
  • Myocarditis
Also, less common:
  • Alcohol abuse
  • Hemochromatosis
  • Thyroid disease
What is the physiological problem in systolic heart failure?
Impaired contractility
What are the causes of diastolic dysfunction? (3)
  • Hypertension → cardiomyopathy
  • Valvular diseases
  • Restrictive cardiomyopathy (eg. amyloidosis, sarcoidosis, hemochromatosis)
What is the physiological problem in diastolic heart failure? (2)
  • ↑stiffness of ventricle
  • Impaired relaxation of ventricle
What does an echocardiogram show in diastolic dysfunction?
Impaired relaxation of ventricle
What causes of heart failure lead to both systolic and diastolic dysfunction?
  • Hypertension
  • Valvular diseases
  • Some restrictive causes (eg. hemochromatosis)
What are symptoms of left-sided heart failure and please explain their etiology? (6)
  • Dyspnea: difficulty breathing 2o to pulmonary congestion/edema
  • Orthopnea: difficulty breathing in recumbent position; relieved by elevation of the head with pillows
  • Paroxysmal nocturnal dyspnea (PND): awakening after 1 to 2 hours of sleep due to acute shortness of breath (SOB)
  • Nocturnal cough (non-production): Worse in recumbent position (same pathology as orthopnea)
  • Confusion and memory impairment: occur in advanced CHF due to inadequate brain perfusion
  • Diaphoresis and cool extremities at rest: occur in desperately ill patients
What are signs of left-sided heart failure and please explain etiology? (7)
  • Displaced PMI: (due to cardiomegaly)
  • Pathologic S3: (ventricular gallop) due to abnormally rapid deceleration of early diastolic left ventricular inflow (highly specific sign of CF) as blood fills non-compliant ventricle
  • S4 gallop: due to the sound of atrial systole as blood ejected into non-compliant ventricle
  • Crackles/rales at lung bases: caused by fluid in alveoli; indicates pulmonary edema (which indicates at least moderate HF)
  • Dullness to percussion (due to pleural effusion)
  • Decreased tactile fremitus (due to pleural effusion)
  • ↑intensity S2 due to ↑pulmonic component due to pulmonary HTN
What are the signs and symptoms of right-heart failure? (6)
  • Peripheral pitting edema: pedal edema lacks specificity as an isolated finding (can be due to vascular insufficiency)
  • Nocturia: due to ↑venous return with elevation of legs
  • Jugular venous distension (JVD)
  • Hepatomegaly/hepatojugular reflex
  • Ascites
  • Right ventricular heave
What is the relationship between left and right heart failure given enough time?
With enough time, left-sided heart failure will always lead to right-sided heart failure (and vice versa).
Describe the New York Heart Association (NYHA) classification of heart failure.
  • Class I: Symptoms only with vigorous activities.
  • Class II: Symptoms occur with prolonged or moderate exertion.
  • Class III: Symptoms occur with usual activities of daily living.
  • Class IV: Symptoms at rest.
What 5 tests would you order for a new patient with CHF?
  • CXR (pulmonary edema, cardiomegaly, r/o COPD)
  • ECG
  • Cardiac enzymes
  • CBC (anemia)
  • Echocardiogram (estimate EF, r/o pericardial effusion)
BNP is released from what in response to what?
BNP is released from the ventricles in response to ventricular volume expansion and pressure overload.
BNP is useful for distinguishing dyspnea due to which 2 conditions?
CHF vs COPD
What are signs of CHF on a CXR? (4)
  • Prominent interstitial markings
  • Cardiomegaly
  • Kerley B lines: short horizontal lines at periphery of lung near the CVA
  • Pleural effusion
Why is an echocardiogram useful in CHF? (4)
  • Determines whether systolic or diastolic dysfunction predominates
  • Determines whether cause of CHF is due to a pericardial, myocardial or valvular process
  • Estimates ejection fraction (EF)
  • Shows chamber dilation and/or hypertrophy
Describe the utility of ECG in CHF.
Usually non-specific, but can demonstrate chamber enlargement.
  • Arrythmias are common (eg. atrial fibrillation)
  • May be ↓voltage
What is radionuclide ventriculography (ie. MIBI scan using technetium 99-m) useful for?
  • What other test provides the same information? 
  • MIBI tells you the ejection fraction (EF) with excellent accuracy.
  • However, echocardiogram also tells you the EF with pretty good accuracy.
Provide 2 reasons why cardiac catheterization (ie. coronary angiography) might be ordered in CHF work-up?
  • Shows degree of systolic relative to diastolic dysfunction and this can help to clarify the cause of CHF if the other tests do not provide a clear picture
  • Rules out CAD as cause of CHF
What role might stress testing having in a CHF workup? (1)
  • Identifies cause of dyspnea: whether it is due to a cardiac cause (ie. ischemia secondary to CAD) rather than pulmonary cause (ie. CHF).
  • Quantitates level of conditioning
  • Assesses dynamic response of heart
What lifestyle changes are used in treatment of systolic dysfunction in CHF? (7)
  • Sodium restriction (<4g/day)
  • Weight loss
  • Smoking cessation
  • Restricting alcohol use
  • Exercise
  • Daily weighing
  • Annual flu and pneumococcal vacines
Name all drug classes that may be used in treatment of CHF. (7)
  • Diuretics (loop and thiazide)
  • Spironolactone
  • ACEi
  • ARBs
  • β-blockers
  • Digitalis
  • Hydralazine
What drug class provides the most effective means of symptomatic relief in CHF?
Diuretics
What did the RALES trial show about spironolactone and mortality in CHF?
  • When is spironolactone indicated?
Spironolactone reduces mortality in CHF patients with Class III or Class IV heart failure.
  • May be indicated in severe HF
When is spironolactone contraindicated? (1)
Renal failure
  • When you use it, you need to monitor serum potassium and renal function 
What happens to potassium levels with spironolactone use?
↑K+
Regarding ACEi:
  • When are ACEi indicated in HF?
  • What effects do ACEi have on vasculature, preload and afterload
  • ACEi indicated in LV systolic dysfunction when EF <40%
  • ↑venous dilation
    ↑arterial dilation
    ↓preload
    afterload
What effects do ACEi have on mortality and symptoms?
  • Prolong survival
  • ↓mortality
  • ↓symptoms

Regardless of whether HF is mild, moderate or severe.
Which HF patients should be on an ACEi?
All patients with heart failure
What do you monitor for HF patients on ACEi? (4)
  • BP (watch: hypotension)
  • Potassium (watch: ↑K+)
  • BUN (watch: kidney injury)
  • Creatinine (watch: kidney injury)
When do you use ARBs in HF?
When patient cannot tolerate an ACEi
  • ACEi > ARB
  • However, ARB gives some mortality reduction and should be used if ACEi cannot be 
What is the initial combination of drugs in HF patients? (2)
  • Diuretic
  • ACEi
Describe the role of β-blockers in HF, with regard to mortality and symptoms.
β-blockers:
  • ↓symptoms in HF
  • ↓mortality if HF due to past MI

Other benefits include:
  • ↓arrythmias
  • ↓O2 consumption
  • ↓tissue remodeling
Which patients get β-blockers?
  • Stable patients
  • NYHA Class I, II and III (but not IV)
How does digitalis affect the heart?
Positive ionotrope
Describe role of digitalis with regard to mortality and symptoms in HF.
  • Digitalis has no effect on mortality
  • Short-term ↓symptoms
When is digitalis indicated in a HF patient? (3)
  • Severe CHF
  • Patients with EF <40%
  • Severe atrial fibrillation
Basically, digitalis is for patients with EF <40% who have symptoms despite ACEi, β-blocker, aldosterone antagonist and diuretic.
When is hydralazine used in HF?
  • Used for ↓mortality in select patients, when ACEi cannot be used.
What medications have been shown to lower mortality in HF? (5)
  • ACEi
  • ARBs
  • β-blockers
  • Aldosterone antogonists (spironolactone)
  • Hydralazine
What role do calcium-channel blockers play in HF management?
None
  • They can increase mortality 
What medications are contraindicated in CHF? (3)
  • Metformin (may cause lethal lactic acidosis)
  • NSAIDs (may increase risk of CHF exacerbation)
  • Thiazolidinediones (fluid retention)
What is the most common cause of death in CHF?
Sudden cardiac death
Which HF patients require an ICD to mitigate risk of sudden cardiac death?

Moderate severity post-MI patients with reduced EF
  • Post-MI patients
  • >40 days after MI
  • EF <35%
  • Class II or III
What is the difference between a cardiac resynchronization therapy (CRT) and an ICD?
CRT is for people with same indications as ICD, as well as long QRS
  • Provides biventricular pacing 
x of y cards Next > >> >|