Cardiovascular Flashcards
What are the 4 abnormalities that characterize Tetrology of Fallot
- VSD
- Overriding aorta over the right and left ventricles
- Right ventricular outflow tract obstruction
- Right ventricular hypertrophy
What is the embryologic mechanism that causes TOF?
Deviation of the infundibular septum
What forms most of the inferior surface of the heart? Which vessel supplies this area?
Inferior wall of the left ventricle. Supplied by the posterior descending artery, which derives from the right coronary artery in 85-90% of people (right dominant)
What is the pathogenesis of an abdominal aortic aneurysm?
oxidative stress, vascular smooth muscle apoptosis, and chronic transmural inflammation of the aorta.
Inflammatory cells release matrix metalloproteinases and elastases that degrade extracellular matrix components leading to weakening and progressive expansion of the aortic wall
First aortic arch
Regresses almost completely, gives rise to a portion of the maxillary artery
Third aortic arch
Forms the common and proximal internal carotid arteries
Fourth aortic arch
Part of the true aortic arch and subclavian arteries
Sixth aortic arch
Pulmonary arteries and the ductus arteriosus
Describe the murmur of aortic stenosis
Systolic ejection type, crescendo-decrescendo. Starts after the first heart sound and typically ends before the A2 component of the 2nd heart sound.
The intensity of the murmur of aortic stenosis is proportional to what?
The magnitude of the left ventricle to aorta pressure gradient during systole
Murmur of mitral valve stenosis
Opening snap following by a diastolic rumbling murmur best heard over the apex
What is the physiologic cause of a PFO?
Incomplete fusion of the septum primum and septum secundum
What causes ASD?
Aplasia of the septum primum or septum secundum during development
Mechanism of fibrates
They lower triglycerides by activating PPAR-alpha, which leads to decreased hepatic VLDL production and increased LPL activity
Rerpurfusion injury occurs secondary to what processes?
Oxygen free radical generation, mitochondrial damage, and inflammation
What genetic disorder is associated with coarctation of the aorta?
Turner Syndrome (45, XO)
Where do type A aortic dissections usually originate?
Ascending aorta, usually originates in the sinotubular junction
Where do type B aortic dissections usually originate?
Usually near the origin of the left subclavian artery
Cardiac auscultation for mitral stenosis
Loud first heart sound, an early diastolic opening snap after the second heart sound, and a low pitched diastolic rumble beast heard at the cardiac apex
What physical exam findings can be seen in patients with aortic regurgitation?
Bounding peripheral pulses and head bobbing with each heartbeat
How does atrial fibrillation present on ECG?
Absent P waves, irregularly irregular R-R intervals, and narrow QRS complexes
What mediates phase 0 depolarization in cardiac pacemaker cells?
Inward influx of calcium
What are the findings associated with cardiac tamponade?
Hypotension, elevated JVP, muffled heart sounds. Pulsus paradoxus. Echo shows pericardial fluid accumulation with late diastolic collapse of right atrium.
What is pulsus paradoxus?
Exaggerated drop in systolic BP (>10) during inspiration
When does dystrophic calcification occur?
In damaged or necrotic tissue in the setting of normal calcium levels
What causes an S3 sound?
Increased LA pressure
Janeway lesions
Nontender, macular, erythematous lesions typically located on the palms and soles of pts with acute infective endocarditis. Result of septic embolization from valvular vegitations
Flecainide
Class 1c antiarrhythmic used to treat supraventricular tachycardias such as those caused by atrial fibrillation. Block inward sodium current by binding fast sodium channels responsible for phase 0 depolarization. Exhibit use dependence - more intense effects at increased heart rate
Which congenital syndromes are associated with QT prolongation
Romano-Ward Syndrome (aut. dominant, no deafness) and Jervell and Lange-Nielsen Syndrome (aut. recessive, neurosensory deafness)
Why are patients with coarctation of the aorta at increased risk for ruptured intrancranial aneurysms?
Because of increased incidence of congenital berry aneurysms of the Circle of Willis as well as aortic arch HTN
Trousseau syndrome
Migratory superficial thrombophlebitis. Indication of visceral cancer (adenocarcinomas of pancreas, colon, lung)
Which bacteria can cause endocarditis in patients with pre-existing valvular lesions
Viridans streptococci
Which bacteria can cause endocarditis in intact valves?
Staph aureus
Hibernating myocardium
Presence of LV systolic dysfunction due to reduced coronary blood flow at rest that is partially or completely reversible by coronary revascularization
Name the class III antiarrhythmics
Amiodarone, sotalol, dofetilide
Mechanism of class III antiarrhythmics
Block potassium channels and inhibit the outward potassium currents during phase 3 of the cardiac action potential, thereby prolonging repolarization and total action potential duration
Type I collagen
Most prevalant colalgen in the human body and primary collagen in mature scars
How is carotid massage useful for termination of paroxysmal supraventricular tachycardia?
Leads to an increase in parasympathetic tone causing temporary inhibition of sinoatrial node activity, slowing of conduction through the AV node, and prolongation of the AV node refractory period
What forms the majority of the posterior surface of the heart and is adjacent to the esophagus?
Left atrium
What lies posterior to the esophagus and left atrium?
Descending thoracic aorta
Mechanism of carotid sinus massage
Increases vagal parasympathetic tone, which slows conduction through the AV node and prolongs AV node refractory period
Histology showing “areas of myocardium infiltrated by an amorphous and acellular pink material” indicates
Cardiac amyloidosis
What complication can occur 5-14 days after an initial MI?
Left ventricular free wall rupture
Biopsy findings in giant cell temporal arteritis
Granulomatous inflammation of the media
Takayasu arteritis presentation
Predominantly in females under 40. May have low BP and pulses in UE as compared to LE and cold or numb fingers. Typically affects the aortic arch
What is nitric oxide synthesized from?
Arginine, NADPH, and oxygen.
Conversion of angiotensin I to angiotensin II
Occurs in small vessels of the lungs via endothelial bound angiotensin converting enzyme
Failure of what embryologic process leads to transposition of the great arteries?
Spiraling. There is linear rather than spiral development of the aorticopulmonary septum in utero
Describe the location of the aorta in TGA
Aorta is anterior, inferior, and to the right of the pulmonary artery
What causes progressive eccentric hypertrophy of the LV?
Chronic volume overload
What complication can varicose veins cause?
Venous stasis dermatitis
Flow equation
Flow (Q) = P1-P2 x r^4/(viscosity)(length)
What medications prolong the QT interval?
Certain antiarrhythmics (sotalol, quinidine), antipsychotics (haloperidol), and antibiotics (macrolides, fluoroquinolones)
What is pathognomonic for acute rheumatic fever on myocardial biopsy?
Interstitial myocardial granuloma, or Aschoff body
Presentation of acute rheumatic fever
Pancarditis causing nonspecific fever, fatigue, anorexia, tachycardia, tachypnea, hypotension.
Lethargy, confusion, nausea, decreased appetite, vomiting , vision problems, arrhythmias, hyperkalemia. Signs of toxicity of what medication?
Digoxin
Hormone sensitive lipase
Found in adipose tissue. Drives breakdown of stored triglycerides into free fatty acids and glycerol. In times of starvation, it provides substrates for hepatic gluconeogensis and ketone body formation
early systolic, high frequency click over the right 2nd interspace
Bicuspid aortic valve
Right-sided face and arm swelling and engorgement of subcutaneous veins on the same side of the neck
obstructed right brachiocephalic vein
ST elevations in leads I and aVL
Occlusion of the left circumflex artery
What supplies the lateral aspect of the left ventricle?
Left circumflex artery
What is the most common heart defect in patients with Down Syndrome?
Complete AV canal defect - comprised of ASD, VSD, and a common AV valve
Cannulation above the inguinal ligament can lead to what complication?
Retroperitoneal hemorrhage
How long does it take for loss of cardiomyocyte contractility after onset of total ischemia?
60 seconds
What are the most important factors involved in coronary blood flow autoregulation?
Adenosine and nitric oxide (NO)
What are the most heavily involved vessels in humans with atherosclerotic plaques?
The abdominal aorta > coronary arteries > popliteal artery > internal carotid arteries > circle of Willis
What are common complications of varicose veins?
Edema, stasis dermatitis, skin ulcerations, poor wound healing, and infections
How is suspected carcinoid syndrome diagnosed?
Elevated 24-hour urinary 5-HIAA level
What are the heart findings associated with carcinoid syndrome?
Pathognomonic plaque-like deposits of fibrous tissue occur most commonly on the endocardium, leading to tricuspid regurgitation, pulmonic valvulopathy, and right sided heart failure
How does hyperplastic arteriosclerosis present?
Onion-like concentric thickening of the walls of arterioles
What are the findings associted with a large PDA complicated by Eisenmenger syndrome?
Differential clubbing and cyanosis without blood pressure or pulse discrepancy
What mediates calcium efflux from cardiac cells prior to relaxation?
Na+/Ca2+ exchange pump and sarcoplasmic reticulum Ca2+-ATPase pump
Which cells in an atherosclerotic plaque are capable of synthesizing collagen and matrix components?
Vascular smooth muscle cells (VSMCs)
Low pitched, holocystolic murmur at the left sternal border. Accentuates with handgrip maneuver.
Ventricular septal defect (VSD)
Blood supply to posteromedial papillary muscle
Supplied solely by the posterior descending artery
Best ausculatory indicator of the degree of mitral stenosis
Interval from S2 (A2 component) to opening snap
Hypotension with pulsus paradoxus, elevated JVP, and muffled heart sounds
Beck’s triad. Presentation of cardiac tamponade
Development of an atherosclerotic plaque
Activated macrophages, platelets, and endothelial cells release growth factors that stimulate recruitment of smooth muscle cells from the arterial wall media and their subsequent proliferation in the intima
What causes dynamic left ventricular outflow tract obstruction in patients with hypertrophic cardiomyopathy?
Due to abnormal systolic anterior motion of the anterior leaflet of the mitral valve toward a hypertrophied interventricular septum
Concentric hypertrophy
Uniform thickening of the ventricular wall and narrowing of the ventricular cavity due to increased afterload (chronic HTN, aortic stenosis)
Eccentric hypertrophy
Reduced ventricular wall thickness with an associated increase in chamber size due to volume overload
Lipofuscin
Product of lipid peroxidation, accumulating in aging cells. Yellow-brown, finely granular perinuclear pigment
Harsh, crescendo-decrescendo systolic ejection murmur heard best in the right intercostal space with radiation to the carotids
Aortic stenosis
The ductus arteriousus is derived from which aortic arch?
6th
Episodic, transient attacks of coronary vasospasm producing temporary transmural myocardial ischemia with ST-segment elevation
Prinzmetal (variant) angina
Triggers for prinzmetal angina
Cigarette smoking, cocaine/amphetamines, and dihydroergotamines/triptans
Treatment for prinzmetal angina
Tobacco/drug cessation and vasodilator therapy (nitrates, calcium channel blockers)
Where are the structures located that mediate the pupillary light reflex
Upper midbrain
What are the neural structures that mediate the direct and consensual pupillary light reflex
Optic nerve, pretectal nuclei, Edinger-Westphal nuclei, oculomotor nerve
