Cardiovascular Flashcards
Stimulation of what receptor increases cAMP in cardiac myocytes?
B1
Stimulation of what receptor increases cAMP in vascular smooth muscle cells?
B2
What is the most common cause of coronary sinus dilation?
Elevated right sided heart pressure secondary to pulmonary artery hypertension.
How does moderate coarctation of the aorta present?
In childhood or adolescence with symptoms of lower extremity claudication, blood pressure discrepancy between the upper and lower extremities, and delayed or diminished femoral pulses. May also present with continuous murmurs and pulsatile intercostal collaterals.
What is the mechanism of action of Daptomycin?
It disrupts the bacterial membrane through the creation of transmembrane channels. This causes leakage of intracellular ions leading to depolarization of the cellular membrane and inhibition of macromolecular synthesis and cell death.
What is daptomycin used to treat?
Gram positive organisms- used for treating skin and skin structure infections and bacteremia (with or without endocarditis) due to Staph aureus, including MRSA.
What are the side effects of daptomycin?
Increased CPK, increased incidence of myopathy
Persistent lymphedema with chronic dilation of lymphatic channels predisposes patients to the development of what condition?
Lymphangiosarcoma, a rare malignant neoplasm of the endothelial lining or lymphatic channels.
What is a common complication of transmural myocardial infarction 3-7 days after the onset of total ischemia?
Ruptured LV free wall.
What causes LV free wall rupture following transmural MI?
Coagulative necrosis, neutrophil infiltration, enzymatic lysis of connective tissue substantially weaken the infarcted myocardium.
What three symptoms are characteristic of pericardial tamponade?
Muffled heart sounds, elevated JVP, profound hypotension.
What structures are obstructed in Hypertrophic Cardiomyopathy (HOCM)?
Mitral valve cusp and intraventricular septum. This obstruction is due to abnormal systolic anterior motion of the anterior leaflet of the mitral valve towards a hypertrophied interventricular septum
Describe the genetic inheritance of HOCM and the genes that are mutated.
Autosomal dominant. Mutation in genes for sarcomere proteins (components of thick or thin filaments).
What are the typical presenting symptoms in a patient with HOCM?
Exertional syncope, harsh systolic murmur, asymmetric septal hypertrophy
What murmur is heard in a patient with HOCM?
Systolic ejection murmur
In systolic dysfunction, describe the pathology of heart failure.
Increased blood volume in the heart causes stretching of the atria and ventricles beyond the appropriate stretch to cause maximal contraction by Starling mechanism.
Increased myocardial stretch causes release of what proteins?
ANP from the walls of the atria; BNP from the walls of the ventricles. They both act to activate guanylate cyclase which induces increase in cGMP.
What condition is implicated by an S3 gallop?
Increased left ventricular filling rate during mid diastole or mitral regurgitation.
What is the most common anatomic abnormality that produces mitral regurgitation?
Myxomatous degeneration due to mitral valve prolapse.
Describe the murmur associated with aortic stenosis.
Systolic ejection type crescendo decrescendo murmur.
What determines the intensity of an aortic stenosis murmur?
Intensity is proportional to the magnitude of the left ventricle-to-aorta pressure gradient during systole.
Define sudden cardiac death.
Cardiac arrest that begins within 1 hour of a precipitating event and that ultimately proves fatal.
What induces arrythmias in patients with CAD?
Ischemia that induces electrical instability and a potentially lethal arrythmia.
What is the best indication of severity in mitral regurgitation?
The presence of an S3 gallop. This reflects an increased rate of LV filling due to a large volume of regurgitant flow re-entering the ventricle during mid diastole.