Heart Part 1 Flashcards
The myocardium contains atrial myocytes that have storage granules that contain?
atrial natriuretic peptide
What does atrial natriuretic peptide promote?
arterial vasodilation and stimulates renal salt and water elimination (natriuresis & diuresis) which is beneficial in
the setting of HTN and CHF
What are the 3 types of valvular damage?
- collagen (mitral prolapse)
- nodular calcification (calcific aortic stenosis)
- fibrotic thickening (rheumatic heart dz)
What happens to the myocardium and chambers as we age?
- LV cavity/volume is reduced
- Increased epicardial fat
• Myocardium changes:
- Lipofuscin and basophilic degeneration
What happens to valves as we age?
- Aortic and mitral valves annular CALCIFICATION
- Fibrous thickening
- Mitral leaflets buckle towards Lt atrium –> Increased left atrium size
- LAMBL EXCRESCENCES: small filiform processes form on the
closure lines of aortic and mitral valves, probably resulting
from the organization of small thrombi
What vascular changes happen as we age?
– Coronary atherosclerosis
– Stiffening of the aorta
- Occurs when the heart is unable to pump blood at a rate to meet peripheral demand, or can only do so with increased filling pressure
Congestive heart failure (CHF)
How does Congestive heart failure (CHF) occur?
• Loss of myocardial contractile function (systolic dysfunction)
• Loss of ability to fill the ventricles during diastole (diastolic dysfunction)
How do cardiac myocytes become hypertrophic?
- Sustained pressure or volume overload (systemic HTN or aortic stenosis)
- Sustained trophic signals (Beta-adrenergic stimulation)
What happens in the setting of PRESSURE overload hypertrophy?
Myocytes become thicker, and LV increases thickness concentrically
What happens in the setting of VOLUME overload hypertrophy?
- Myocytes elongate, and ventricular DILATION is seen
* Heart weight best measure of hypertrophy in dilated heart (vs wall thickness)
What is the best measure of hypertrophy in dilated heart?
Heart weight
Hypertrophy of myocytes isn’t accompanied by a matching
increase in blood supply, despite increased energy demand which means that the hypertrophied heart is vulnerable to what?
the hypertrophied heart is vulnerable to ischemia-related
decompensation
Left-sided heart failure is most commonly a result of?
- Myocardial ischemia
- Hypertension
- Left-sided valve Dz
- Primary myocardial dz
Clinical effects of left-sided heart failure are due to?
– Congestion in the pulmonary circulation
– Decreased tissue perfusion
Left-sided Heart Failure:
- Left ventricular dysfunction leads to ? which leads to ?
- Pulmonary congestion and edema can cause ?
- Decreased ejection fraction may result in ? Which stimulates?
- Advanced CHF may lead to ? which leads to ?
• Left ventricular dysfunction leads to left atrial dilation
– This can lead to atrial fibrillation, stasis, thrombus
• Cough, dyspnea, orthopnea, paroxysmal nocturnal
dyspnea
• Decreased ejection fraction may result in decreased glomerular perfusion
– Stimulating release of renin leading to increased volume
– Prerenal azotemia
• Advanced CHF may lead to decreased cerebral perfusion
– Hypoxic encephalopathy
What is the most common cause of right-sided heart failure?
Left-side failure ***
Right-Sided Heart failure:
• ISOLATED right-sided failure results from any cause
of? Examples?
• Isolated right-sided failure results from any cause
of pulmonary hypertension
– Parenchymal lung diseases
– Primary pulmonary hypertension
– Pulmonary vasoconstriction
What occurs in PRIMARY right-sided heart failure?
- pulmonary congestion is MINIMAL (unlike isolated failure!!!)
- the venous system is markedly congested
- Liver congestion (NUTMEG LIVER)
- Splenic congestion leading to splenomegaly
- Effusions involving peritoneal, pleural and pericardial spaces
- Edema, especially in dependent areas (e.g., ankles)
- Renal congestion
What is left-sided heart failure most commonly due to?
Symptoms are mainly a consequence of what?
- ISCHEMIC heart disease, SYSTEMIC HYPERTENSION, MITRAL OR AORTIC VALVE disease, and
primary diseases of the myocardium - Symptoms are mainly a
consequence of PULMONARY CONGESTION AND EDEMA, although systemic hypoperfusion can cause secondary renal and cerebral dysfunction.
Right heart failure is most often due to what?
Symptoms are chiefly related to what?
- Right heart failure is most often due to left heart failure, and less commonly to primary pulmonary disorders
- Symptoms are chiefly
related to PERIPHERAL EDEMA AND VISCERAL CONGESTION
Sporadic genetic abnormalities are the major known causes of what? Examples?
- Sporadic genetic abnormalities are the major known causes of congenital heart disease
- Examples: Turner syndrome, and trisomies 13, 18 & 21
What is the single most common genetic cause of congenital heart disease?
trisomy 21
About 40% patients with Down syndrome have at least one heart defect and it is usually derived from what?
• Usually derived from the second heart field (arterioventricular septae)
– most commonly defects of the endocardial cushion, including ostium primum, ASDs, AV valve
malformations, and VSDs
Congenital Heart Dz:
Notch pathway are associated with a variety of congenital heart defects, including ?
bicuspid aortic valve (NOTCH1 ) and tetralogy of Fallot (JAG1 and NOTCH2)
Congenital Heart Dz:
Fibrillin mutations underlie what syndrome?
Fibrillin mutations underlie MARFAN syndrome—associated with valvular defects and aortic aneurysms
What are some examples of congenital heart disease?
- Left-to-right shunts
- Atrial Septal Defects (ASD)
- Ventricular Septal Defects (VSD)
- Patent Ductus Arteriosus (PDA)
- Right-to-left Shunts
- Obstructive lesions
What are the top 3 most frequent congenital cardiac malformations?
- Ventricular septal defect
- Atrial septal defect
- Pulmonary stenosis
What are the genes and gene product function for:
- ASD or conduction defects
- ASD or VSD
- Tetralogy of Fallot
1.
Gene: NKX2.5
Gene Product Function: Transcription factor
- Gene: GATA4
Gene Product Function: Transcription factor - Gene: ZFPM2 or NKX2.5
Gene Product Function: Transcription factors
What is the most common congenital heart disease?
Left-to-Right Shunts
What are some examples of Left-to-Right shunts?
– ASD
– VSD
– PDA (patent ductus arteriosus)
Common Congenital Left-to-Right Shunts:
- ? increases only RV and pulmonary outflow volumes
- ? and ? cause increased pulmonary blood flow and pressure
- ASD
- VSD and PDA
When do you start noticing symptoms for atrial septal defects?
Usually asymptomatic until adulthood (>30 year old)
90% of all ASDs; center of atrial septum; may be multiple or fenestrated
Secundum ASD