Dr. Houston (Cardio)- Exam 1 Flashcards
What is the pathway of the heart?
What are the different components of heart fibers (histology?
What is cardiomyopathy?
* What is primary and secondary?
Cardiomyopathy: Disease of the myocardium
- Primary Cardiomyopathy – disease manifests directly (idiopathic, genetic, infection, alcohol/drugs)
- 2nd Cardiomyopathy – develops to compensate for other diseases (e.g. hypertension, valve diseases
Dilated cardiomyopathy:
* What are the causes?
Idiopathic, Genetic mutations, Infection, Alcohol/drug abuse
What is the patho behind dilated cardiomyopathy? Txt?
Hypertrophic Cardiomyopathy
* What are the causes?
Most commonly - Autosomal missense mutation in sarcomere protein
Hypertrophic cardio
* What is the patho?
- New cardiomyocytes added parallel
- Causes myocardium becomes thick, heavy, and hypercontractile
- Usually LV hypertrophy (mostly on interventricular septal wall)
- New muscle fills chamber = decreased chamber volume
- New muscle = increased stiffness (less compliant)
- Both = decreased preload = decreased CO
- Classified as Diastolic heart failure
Hypertrophic Obstructive Cardiomyopathy
* What does it cause?
* Decreases what?
* What type of mumor?
* What can happen?
- Interventricular septal wall bloc.
- Mitral valve can be pulled medially (Venturi effect) = decreased SV
- Crescendo-decrescendo mumor
- Ischemia (more muscle, but less efficient CO to coronary arteries
txt of hypertrophic cardio?
Beta blockers, calcium channel blockers, surgery
Restrictive Cardiomyopathy
* What are the causes?
Misfolded cardiac proteins (amyloidosis) – either genetic or w/age, sarcoidosis (granulomas), fibrotic deposits (fibroelastosis), hemochromatosis, ROS-induced inflammation
What is the patho and txt of restrictive cardio?
What are the stages of the slow action potential?
- 4: Na+ funny channels open = Na+ influx = RMP to threshold
- 0: Ca2+ channels open, Ca2+ influx = depol
- 3: K+ channels open = K+ efflux = repol
What are the steps of the fast action potential
4: Na+ influx = RMP to threshold
0: rapid Na+ influx = rapid depol, Na+ channels close
1: K+ (voltage gated) channels open, K+ efflux = repol
2: Ca2+ influx maintains plateau
3: Ca2+ channels close,
K+ channels open = repol
- What is fibrillation?
- What are the causes?
- Fibrillation – quivering or twitching contraction – inefficient for pumping blood
- Causes: Not fully understood. Risk factors - Inflammation of atria via CV disease (hypertension, coronary artery disease, valvular disease). Poor diet/lifestyle. Possible genetic factor.
What is the patho of afib
- What is heart block?
- What are the causes?
Heart block: arrhythmia where electrical signal delayed or blocked
Causes
* Damage or fibrosis to conduction system; Lev’s disease – idiopathic scarring
* Ischemic heart disease - heart attack = hypoxia = cardiomyocyte scar tissue
* Cardiomyopathies, Myocarditis, Medication
What is Atrioventricular block?
- delay/interruption of electrical signal from atria to ventricles
What is first degree, second degree (type 1+2) and third degree?
Bundle branch block
* What is it?
* What are the causes?
What is the patho of bundle branch block?
Paroxysmal supraventricular tachycardia (PSVT)
* What is paroxysm?
* May last how long?
* What are the causes?
- paroxysm = sudden, violent, Tachycardia = rest >100bpm, Supraventricular = in Atria
- may last anywhere from a few minutes to a few days, and some people have no symptoms at all.
- Causes: Stress, overexertion, Alcohol use, Caffeine use, Illicit drug use, Smoking, hyperthryodism, - medications (Digoxin)
What is the patho of Paroxysmal supraventricular tachycardia (PSVT)?
Premature beats
* What are they?
* What are the causes?
- Earlier than normal contraction due to ectopic focus
- Causes: Electrolyte imbalance, ischemic damage, drugs, anxiety, or Reenterant loop
What is the patho of premature beats (PAC and PVCs)?
Sick sinus syndrome (sinus node dysfunction)
* What are the causes?
* What is the patho?
What is first degree, second one and two and third degree SA block
Ventricular tachycardia
* HR?
* What is in a row?
* What happens with high HR?
* What are the causes?
What is the patho for the two types of v tach?
Ventricular fibrillation (VF, Vfib)
* What is fibrillation?
* What are the causes?
* What is the txt?
- Fibrillation – quivering or twitching contraction – inefficient for pumping blood. High risk of sudden cardiac death
- Causes: stress or damage causes cardiomyocyte heterogeneity - medications, illicit drugs, electrolyte
imbalance, ischemia to cardiac tissue - Txt:Defibrillation to depolarize a critical mass of cells back into sinus rhythm
Long QT wave and Torsades de pointes
* What are the causes?
* What is the pahto?
Causes
* Genetic abnormality, medications (channel blockers).
Pathophysiology
* Long QT wave means ventricular repolarization lasts longer than normal in some heart cells
* Due to ion channel problems – dysfunctional L-type Ca2+ channels or Na+ & K+ channel problems
- PVCs can form causes what?
- Can causes polymorphic VT known as what?
- PVCs can form causes reentrant circuits and reentrant tachycardia
- Can causes polymorphic VT known as Torsades de pointes (twisting of points)
Cardiogenic shock
* What are the causes?
MI, obstructive shock – pericadical effusion leading to cardiac tamponade – fluid in pericardial sac - trauma