Heart failure, its causes, structural changes and ECG changes

1. HEART FAILURE
HEART

2. • It is the pathophysiological process in which systolic or/and
diastolic function of the heart as a pump is unable to meet the
metabolic requirements of the tissue for oxygen and substrates
despite the venous return to heart is either normal or increased.
• 5 million Americans have heart failure.
• 500,000 new cases diagnosed each year in US.
• HF is the reason for at least 20% of all hospital admissions among
persons older than 65.

3. • Cardiac output (CO) = Stroke Volume (SV) x Heart Rate (HR)
• SV – determined by preload, afterload and myocardial
contractility
• Preload: Volume of blood in ventricles at end diastole
Depends on venous return
• Afterload: Force needed to eject blood into circulation
Depends upon arterial BP, pulmonary artery
pressure

4. UNDERSTANDING HF
• All organs (liver, lungs, legs, etc.) return blood to heart
• When heart begins to fail/ weaken, unable to pump blood, Forward
fluid backs up and Increase pressure within all organs.
• LUNGS:
• congested -> increase effort to breathe -> fluid
starts to escape into alveoli (pulmonary edema)
-> fluid interferes with O2 exchange (hypoxia) ->
aggravates shortness of breath
• Shortness of breath during exertion may be
early symptoms
• progresses ->later require extra pillows at night
to breathe (orthopnea)
• and experience "P.N.D." or paroxysmal nocturnal
dyspnea
• LEGS, ANKLES, FEET:
• blood from feet and legs -> back-up of fluid
and pressure in these areas, as heart unable
to pump blood as promptly
• as received increase fluid within feet and legs
(pedal/dependent edema) and increase in
weight

6. ETIOLOGY
• Systolic Failure - most common
– Hallmark finding: Decrease in left ventricular
ejection fraction <40% (EF)
• Due to
– Impaired contractile function (e.g., MI)
– Increased afterload (e.g., hypertension)
– Cardiomyopathy
– Mechanical abnormalities (e.g., valve disease)
• Diastolic failure
– Impaired ability of ventricles to relax and fill
during diastole, decrease stroke volume and CO
• Mixed systolic and diastolic failure
– Seen in disease states such as dilated
cardiomyopathy (DCM)
– Poor EFs (<35%)
– High pulmonary pressures
• Biventricular failure
– Both ventricles may be dilated and have poor
filling and emptying capacity

9. PATHOPHYSIOLOGY
A) Cardiac compensatory mechanisms
1. Tachycardia
2. Ventricular dilation
3. Myocardial hypertrophy
B. Homeostatic Compensatory Mechanisms
Activation of Sympathetic Nervous System
1. In vascular system resulting in vasoconstriction
2. Kidneys
• i. Decrease renal perfusion-> Renin angiotensin release
• ii. Aldosterone release-> Na and H2O retention
3. Liver
• i. Stores venous volume causing ascites, hepatomegaly
• Increase Na-> release of Anti diuretic hormone
• (ADH)
• Release of atrial natriuretic factor (ANP) and BNP-> Na
and H20 excretion
• Thus Prevents severe cardiac decompensation

10. C) Neurohormonal responses:
Endothelin - stimulated by ADH, catecholamines, and
angiotensin II
• Arterial vasoconstriction
• Increase in cardiac contractility
• Hypertrophy

13. • Ventricular remodeling/ cardiac
remodeling
– Refers to the changes in size,
shape, structure and physiology of
the heart after injury to the
myocardium
-- results in Mitral regurgitation
(systolic murmur)

14. FACTORS AGGRAVATING HEART FAILURE
• Myocardial ischemia or infarct
• Dietary sodium excess
• Excess fluid intake
• Medication noncompliance
• Arrhythmias
• Intercurrent illness (e.g. infection)
• Conditions associated with increased metabolic demand (e.g. pregnancy, thyrotoxicosis,
excessive physical activity)
• Administration of drug with negative inotropic properties or fluid
retaining properties (e. NSAIDs, corticosteroids)
• Alcohol

15. CLASSIFICATION SYSTEMS

17. CLINICAL CLASSIFICATION
• According to the course of disease
Acute HF
Chronic HF
• According to the cardiac output (CO)
Low-output HF
High-output HF
• According to the location of heart
failure
Left -side heart failure (LHF)
Right-side heart failure (RHF)
Biventricular failure (whole heart failure)
• According to the function impaired
Systolic failure
Diastolic failure

18. CAUSES
• Impaired cardiac function
Coronary heart disease
Cardiomyopathies
Rheumatic fever
Endocarditis
1. Increased cardiac workload
• Hypertension
• Valvular disorders
• Anemias
• Congenital heart defects
2. Acute non-cardiac conditions
• Volume overload
• Hyperthyroid, Fever, infection
• Systolic versus Diastolic
– Systolic - loss of contractility get decease CO
– Diastolic - decreased filling or preload
3. Acute versus Chronic
– Acute MI
– Chronic Cardiomyopathy

19. LEFT VENTRICULAR FAILURE
Pulmonary congestion + low cardiac output
• Symptom:
Dyspnea
Orthopnea
Paroxysmal nocturnal dyspnea
• Sign
Enlargement of LV
gallop rhythm
Systolic murmur in apex
Dry rales
Moist rales

20. RIGHT VENTRICULAR FAILURE
• Symptom of gastrointestinal
• Symptom of Renal
• Pain in hepatic area
• Dyspnea
• Hepatojugular reflux
• Hepatomegaly
• Edema
• pleural fluid and ascites

21. BIVENTRICULAR FAILURE
• LV failure + RV failure
• Symptoms: Shortness of breath
• Risk Factors: Coronary artery disease;
Hypertension

23. SYMPTOMS OF HEART FAILURE

24. DIAGNOSIS
• 6 minutes walk test (6MWT)
• 6MWT<150 m Serious cardiac dysfunction
• 6MWT 150~425 m Moderate cardiac dysfunction
• 6MWT 426~550 m Mild cardiac dysfunction

25. INITIAL LAB WORKUP INCLUDES
• 1. CBC
Serum electrolytes (including calcium and magnesium)
Blood urea nitrogen (BUN) and serum creatinine (Cr)
Glucose, cholesterol, lipoproteins, TAGs
Cardiac Troponins (A and T)
• 2. Echocardiography
• 3. Electrocardiograph
• 4. Stress tests
• 5. Cardiac CT
• 6. Cardiac MRI
• 7. Coronary angiography

26. ECG CHANGES

31. Thank you
--Akshmala Sharma
(Group 18)
THANK YOU
AKSHMALA
SHARMA