CHF- Melissa (3)* Flashcards
5 causes of cardiac dysfunction:
- pump failure (weak myocytes, inability to relax)
- Obstruction of flow ( ^ after load)
- Regurgitant flow ( ^ preload)
- Conduction anomalies
- Ventricular/ Vascular rupture (discontinuity of system)
3 mechanisms by which the heart accommodates for ^ hemodynamic burden or myocardial contractility change:
- Frank Starling
(^ preload = ^ dilation = ^contraction) - Hypertrophy
(physiologic / pathologic) - Neurohumoral Activation
(NE, Renin/ANG/Aldo, ANP)
Generally, what structural change in the heart precedes failure?
What are 2 causes of this change?
Hypertrophy –> Heart failure
- ^ Mechanical workload
- ^ Trophic signals–> ^ protein synthesis–> ^ # sarcomeres
Describe the CONCENTRIC pattern of cardiac hypertrophy:
- 2 most common causes
- Gross morphology
- Sarcomere arrangment
“Pressure Overlaod Hypertrophy”
- Causes: HTN, Aortic stenosis
- ^ wall diameter, normal/ smaller cavity
- Sarcomeres parallel to long axes of myocytes
Describe VOLUME-OVERLOAD cardiac hypertrophy:
- 2 most common causes
- Gross morphology
- Sarcomere arrangment
*Is it always dangerous?
- Causes: Mitral/ Aortic valve regurgitation
- +/- increase in wall diameter, ventricular dilation
- Sarcomeres assemble in seres (side-by-side) w/ existing
*may be caused physiologically by aerobic exercise
Which type of hypertrophy is a major risk for sudden cardiac death? What does it look like on EKG?
Left ventricular hypertrophy
Leads V2/3: see S waves > 30 mm.
Why is pathological cardiac hypertrophy dangerous to the heart (3)?
- No capillary growth to meet new O2/ nutrient demands
- Hypertrophied myocytes need more O2, nutrients, mitochondria than normal
- ^ Fibrous tissue (less elastic)
4 possible outcomes of sudden cardiac hypertrophy:
- inadequate organ perfusion (decompensation)
- cardiac failure/sudden death
- arrhythmia
- neurohumoral stimulation
What causes physiological cardiac hypertrophy?
What type of hypertrophy is it + 2 reasons why it isn’t dangerous?
Aerobic* exercise (vs static) & pregnancy–
volume load hypertrophy
1. ^ capillary density to accommodate
2. DECREASED resting HR and blood pressure
Does static exercise cause physiological hypertrophy?
Yes, but with more detrimental effects!
Causes concentric/ pressure overload hypertrophy, aerobic causes volume overload hypertrophy.
What are the two types of heart failure?
- Forward failure–> poor perfusion
2. Backward failure–> pulm + peripheral edema
Most common cause of rt. heart failure?
Lt. heart failure
Which side of the heart fails more often? What is the ultimate result (2)?
LEFT HEART FAILURE–>
- Congestion of pulmonary circulation
- Poor peripheral blood flow
Left sided heart failure effects on the HEART:
2 anatomical changes + 1 heart sound
- Hypertrophy of Lt ventricle (except mitral valve stenosis)
- S3 heart sound (^ blood volume/ stiff ventricle)
- Enlarged Lt atrium (A fib, stasis, embolus to brain)
What can enlargement of the Lt atrium cause as a result of L heart failure? (2)
A fib–> stasis–> thrombosis –> stroke
Also- compression of esophagus + left recurrent laryngeal nerve = hoarseness and dysphagia (FA)
Hoarse voice was a practice questions one of the few I got right: thanks, First Aid Guy!
What causes the S3 sound heard during left heart failure?
What does it sounds like?
^ blood in LV or stiff LV
Sound: “Ken-Tuck-y”, early diastolic murmur due to ^ ventricle filling pressure
*NOTE: this sound can be normal in kiddos or athletes.
Left sided heart failure effects on the LUNG:
- What do you see on X-ray ?
- What do you see on tissue biopsy?
MOST EFFECTED ORGAN
^ pressure in pulm vv. –> pulm congestion + edema
- Kerley B lines on X-ray (interstitial transudate)
- Heart failure cells (Hemosiderin laden MQs)
3 clinical manifestations of L heart failure in the lungs:
- cough
- orthopnea
- paroxysmal nocturnal dyspnea
Left sided heart failure effects on kidneys:
- DECREASED renal perfusion–>
- ^ RENIN prodxn by JGA–>
- ^ ALDO–>
- ^ Na + H2O retention–> ^ Interstitial fluid volume–>
- ^ Pulm edema, ^ BUN, ^ Cr
Release of what molecule can be checked to dx. heart failure?
BNP
Left sided heart failure effects on brain:
Occur with advanced disease
Decreased perfusion–> Hypoxic encephalopathy
What is the most common cause of L Heart failure: systolic or diastolic dysfunction?
systolic (LV) dysfunction + insufficient stroke volume
What is the #1 cause of L heart failure + 2 other causative systolic dysfunctions:
What do these problems do the the ejection fraction?
1: ISCHEMIC HEART DISEASE
- HTN
- Dilated cardiomyopathy
- DECREASED EF w/ DECREASED SV
3 diastolic dysfunctions that lead to L heart failure:
What do these problems do to the ejection fraction?
- Massive LV hypertrophy
- Myocardial fibrosis
- Constrictive pericarditis
(All things that prevent the heart from stretching)
*DECREASED SV w/ possibly normal EF
