Cardiology #1 (Cardiomyopathies & Congenital Heart Disease) Flashcards
Explain the pathophysiology of dilated cardiomyopathy.
What are some causes of this (think of the 6D’s).
Also explain some symptoms.
Systolic dysfunction leading to a weak dilated heart. The ventricles cannot contract well –> poor EF
-The heart dilates to compensate for the weak ventricles (contraction problem)
EtOH, postpartum state, cocaine use, Doxirubicin, Vitamin B1 (thiamine) deficiency, Idiopathic (MC), Viral (Coxsackievirus), Radiation
Systolic heart failure symptoms: weakness, fatigue, SOB, dyspnea, orthopnea, DOE, (LHF). Peripheral edema, JVD, hepatomegaly (RHF).
S3 gallop and crackles.
What diagnostics are done for dilated cardiomyopathy and what do they show?
CXR: cardiomegaly, pulmonary congestion (fluffy infiltrates)
Echo (DOC): LV dilation, decreased EF, thin ventricular walls
ECG: LVH, tachycardia, arrhythmias (convex or inverted ST segment)
What kind of cardiomyopathy does alcohol consumption cause?
Dilated Cardiomyopathy
What are some health maintenance measures you can educate the patient on to avoid dilated cardiomyopathy?
Limit alcohol consumption
Control BP, lipids, and DM
Increase Exercise
Treat underlying disorder
What is the treatment for dilated cardiomyopathy?
Standard HF Treatment
-BASH
–BB
–ACEi
–Spironolactone
–Hydralazine + Nitrates
-Diuretics, Digoxin for symptoms
-Sodium restriction
-AICD if EF < 30%
-Cardiac transplant may be needed
What studies should you get for postpartum cardiomyopathy?
Echo and BNP (This is pregnancy related dilated cardiomyopathy)
What is stress (Takotsubo) Cardiomyopathy?
What is the pathophysiology behind this condition?
Transient systolic dysfunction of the LV that may imitate an MI but is in the absence of CAD or evidence of plaque rupture.
Catecholamine surge during times of extreme emotional or physical stress
What are the main risks of stress cardiomyopathy
Postmenopausal state
Exposure to physical or emotional stress
Symptoms of stress cardiomyopathy
-Substernal CP
-Dyspnea
-Syncope
-Indistinguishable from MI
For stress cardiomyopathy, often the cardiac enzymes are elevated. However, what does a coronary angiography show?
No plaque rupture or coronary artery disease
Treatment for stress cardiomyopathy
-Much like ACS: Aspirin, BB, Nitro, Heparin, and coronary angiography to rule out MI
-Short Term: Conservative, supportive due to transient nature
BB or ACEI for 3-6 months
Explain what restrictive cardiomyopathy is and what the main causes are
Diastolic dysfunction in a non-dilated ventricle which impedes ventricular filling (decreased compliance due to stiffness)
Infiltrative Disease: Amyloidosis (MC), Sarcoidosis, Hematochromatosis, Scleroderma, Fibrosis = deposits in the heart
-Also other causes are radiation and chemotherapy
Symptoms of Restrictive cardiomyopathy
-Right sided HF > Left sided HF
–Peripheral edema, JVD, Ascites, GI, hepatomegaly
–Dyspnea
–Kussmaul’s Sign: increase in JVP with inspiration
An echo can be done for restrictive cardiomyopathy. What is seen on an echo and what is seen if the cause is Amyloidosis?
Usually, non-dilated ventricles with normal thickness, diastolic dysfunction, and marked dilation of both atria.
Amyloidosis: bright speckled myocardium with amyloidosis
What is the definitive diagnostic for restrictive cardiomyopathy? What is seen with amyloidosis?
Endomyocardial biopsy
Amyloidosis: apple green birefringence with Congo Red stain
Treatment for restrictive cardiomyopathy
-Treat underlying disease
-Diuretics for symptoms can be given
In hypertrophic cardiomyopathy, what is the reasoning behind it? Also, it is what type of inheritance pattern and what is the mutation in that causes this condition?
Ventricles are too thick, impedes filling –> diastolic dysfunction (mostly LV)
Autosomal dominant pattern
Mutation in the sarcomere genes
Symptoms of HCOM
-Dyspnea (MC), Angina, Arrhythmias, sudden cardiac death during exertion
-Exercise induced syncope due to V-Fib
What does the murmur with HCOM sound like and why? What maneuvers make the murmur increase? Decrease?
Harsh systolic murmur at LSB
-Increased murmur intensity with decreased venous return (standing, Valsalva) = heart is smaller. The Aorta contracts and leads to more turbulent flow
-Decreased murmur intensity with increased venous return (leg raise, supine, and squatting) = bigger heart.
-Loud S4, pulsus bisferens (double pulse)
What does an echo for HCOM show?
EKG?
CXR?
Asymmetrical ventricular wall thickness (septal hypertrophy) 15 mm or more
LVH
Cardiomegaly
Treatment for HCOM? Medical vs Surgical
BB are first line (slow rate of contraction and rate)
AICD for ventricular arrhythmias
Myomectomy if young; alcohol septal ablation is an alternative
What are some recommendations for those with HCOM (things they should avoid, things they should do, etc.)
Avoid dehydration, exercise, exertion
Caution with Digoxin, Nitrates, and Diuretics (positive inotropes) because they lower LV volume and close it off even more!
Explain fetal circulation of the heart
Fetal circulation uses right to left shunts
-Fetus gets oxygen from the placenta via the umbilical vein. The oxygenated blood goes to the fetal RA and 2 shunts help it bypass the nonfunctioning lungs
-Foramen ovale (between two atria) shunts 2/3 of blood from RA–> LA –> LV –> aorta to supply head
-Ductus Arteriosus shunts from pulmonary artery to aorta (systemic circulation)
What happens at birth when the baby cries?
Oxygen enters the lungs, pulmonary vascular resistance decreases, and then both shunts begin to close!