Week 1 Block 7: PCR

Question 1

(1) Dx: sudden onset heart palpitations, heart rate 160/min and regulator, bp 100/70 mmHg (2) Explain Tx: gentle neck massage just below angle of right mandible produces improvement of condition, heart rate now 75/min & bp 120/80 mmHg (3) Other Tx options

Answer 1

(1) Paroxyxmal supraventricular tachycardia (PSVT) (the most common paroxysmal tachycardia) due to AV re-entrant circuits(2) Carotid massage - increase parasympathetic, prolonging AV node refractory period (3) adenosine in hospital setting, but other vagal maneuver such as Valsava works too

Question 2

(1) Wernicke-Korsakoff pt pop (2) Infantile beriberi sx (3) Dry vs. Wet Adult beriberi (4) Assoc. vitamin

Answer 2

(1) alcoholics (2) ages 2-3 mo., fulminant cardiac syndrome with cardiomegaly, tachycardia, cyanosis, dyspnea, and vomiting (3) Dry - symmetrical peripheral neuropathy accompanied by sensory and motor impairments, especially distal extremities; Wet - neuropathy, cardiac involvement (e.g., cardiomegaly, cardiomyopathy, congestive heart failure, peripheral edema, tachycardia)

Question 3

(1) Most important mediator of coronary vascular dilation in large arteries and pre-arteriolar vessels (2) How it is made & where (3) Its mechanism (4) another vasodilatory element in small coronary arterioles (5) Other local factors influencing coronary blood flow

Answer 3

(1) Nitric oxide (2) synthesized from arginine and oxygen by endothelial cells & (3) causes vascular smooth muscle relaxation by guanylate cylase mediated cGMP second messenger system (4) Adenosine (5) Prostaglandins, Serotonin, ANS neurotransmitters, bradykinin, mechanical shear stress, thrombin

Question 4

S3 sound: (1) frequency (2) physiology v. pathologic contexts (3) how to accentuate sound

Answer 4

(1) Low frequency sound (2) physiologic in younger individuals; typically pathologic in older adults, & in these patients, generally results form left ventricular systolic failure or restrictive cardiomyopathy (3) Left decubitus position and fully exhale

Question 5

(1) Common cause of aortic stenosis (2) Classic auscultatory findings in aortic stenosis pts & where its heard best & to where it radiates

Answer 5

(1) Bicuspid aortic valve (2) Harsh, crescendo-descrescendo systolic ejection murmur heard best in right second intercostal space with radiation to carotids

Question 6

(1) Name & Mechanism of Phase 4 in action potential of pacemaker cells (2) 2 substances that reduce rate of spontaneous depolarization in cardiac pacemaker cells

Answer 6

(1) Spontaneous depolarization: occurs due to closure of K+ channels, slow influx of Na+, and opening of T- and L- type Ca++ channels (2) Acetylcholine and Adenosine

Question 7

(1) Ion(s) that mediate phase 0 depolarization of pace maker cells (2) How phase 0 depolarization of non-pace maker cells differ (give 2 examples of these kinds of cells)

Answer 7

(1) Inward flux of Ca++ (2) Inward Na+ current (e.g., cardiomyocytes, Purkinje cells)

Question 8

(1) When does most of blood supply to hear occur & what is a critical factor for determining coronary blood flow

Answer 8

(1) Diastole; Duration or length of diastole (2)

Question 9

Most common site of aortic rupture

Answer 9

Aortic isthmus (connection between ascending and descending aorta distal to where left subclavian artery branches off the aorta)

Question 10

Aortic regurgitation: (1) characteristic murmur (2) most common causes in developed countries

Answer 10

(1) Early diastolic murmur (2) Aortic root dilation or bicuspid aortic valve in developed countries

Question 11

In A-fib, what determines ventricular contraction rate?

Answer 11

AV node refractory period

Question 12

Aortic stenosis: (1) Murmur characteristic (2) Duration (3) Factor impacting intensity (4) Possible presentation/complication

Answer 12

(1) Systolic ejection-type, crescendo-descrescendo murmur (2) Starts after 1st heart sound and typically ends before A2 component of second heart sound (3) Intensity of AS murmur proportional to magnitude of left ventricle to aorta pressure gradient during systole

Question 13

(1) PCWP measures (2) Normal measure (3) Heart abnormality that leads to abnormal meas

Answer 13

(1) Left atrial end diastolic pressure (LAEDP) (2) LAEDP is nearly equal to LV end diastolic pressure (LVEDP) (3) Mitral stenosis elevates LAEDP and PCWP relative to LVEDP

Question 14

(1) Dx/Explain: Caucasian newborn born to 22 yo primigravida has severe tachycardia and cyanosis, PE shows irritable child with continuous, machine-like murmur appreciated between scapulae, Endocardiography shows aorta that lies anterior to and right of pulmonary artery (2) Mechanism/Defect

Answer 14

(1) Transposition of great arteries (TGA): echocardiogram showing aorta lying anterior to and to right of pulmonary artery is diagnostic (2) TGA results from faildure of fetal aorticopulmonary septum to spiral normally during septation of truncus arteriosus, and produces life-threatening cyanosis at birth

Question 15

PDA: (1) conditions its associated w/ (2) tx to close it (3) tx to keep it open

Answer 15

(1) Prematurity & congenital rubella infx (2) Indomethacin & ibuprofen (NSAIDS) - by inhibiting PGE1 synthesis (3) Prostaglandins (PGE1) maintain PDA

Question 16

Dx/Explain: 34 yo Caucasian male with recent-onset dyspnea and fatigue, PMH mild respiratory illness one week ago, bp 80/60 mmHg, pulse 120 regular but weak, pulse becomes undetectable to palpitation during each inspiration, jugular veins distended, lungs clear to auscultation

Answer 16

Cardiac tamponade: (1) Hypotension (2) Distended neck veins (3) Distant/muffled sounds on auscultation = Beck’s triad; Note: Constrictive pericarditis could lead to tamponade, but would have been chronic process, not this acute

Question 17

Acute versus chronic mitral regurgitation: (1) Left atrial compliance (2) Complications

Answer 17

Acute: (1) near-normal LA compliance (2) pulmonary hypertension & pulmonary edema; Chronic: (1) adaptive increase in LA volume and compliance (2) less prone to pulmonary hypertension & pulmonary edema, more prone to atrial fibrillation & mural thromboembolism

Question 18

Dx/Explain: 63 yo male with severe dyspnea, orthopnea, & fatigue. suffered MI 6 mo ago & not been compliant with meds since. PE: bp 170/100 mmHg & HR 100 beats per min. Auscultation: crackles at lung bases, S3 gallop, and II/VI holosystolic murmur over apex. After initial tx with diuretics and vasodilators, patient’s condition improves significantly. next morning, no appreciable gallops or murmurs

Answer 18

Functional mitral regurgitation: Acute hemodynamic changes can produce functional heart murmurs, in absence of any fixed valve lesion. Dilatation of left ventricle in response to increased preload can result in functional mitral regurg., which can be eliminated by preload reduction and reduced by afterload reduction.

Question 19

(1) Dx: 52 yo male periodic substernal chest pain precipitated by fast walking, especially uphill or against wind, pain remits following 5 min of rest, PMH htn and smoking, BP 140.80 mmHg, Pulse 80 beats per minute, lungs clear to auscultation, no heart murmurs heard, no peripheral edema (2) Explain athogenetic mechanism

Answer 19

(1) Stable angina (2) Stable angina: fixed atherosclerotic plaques obstructs >= 75% of coronary artery lumen; Plaques occluding

Question 20

(1) Age at which congenital bicuspid valve patients present with calcific aortic stenosis (2) Compare/Contrast to calcific stenosis of normal aortic valves

Answer 20

(1) Beginning in sixth decade (2) Senile calcific stenosis of normal aortic valves generally becomes symptomatic in 8th decade

Question 21

Inheritance of familial hypercholesterolemia & its defect

Answer 21

Autosomal dominant LDL receptor defect

Question 22

List steps of normal jugular venous pulse curve.

Answer 22

a = right atrial contraction; c = bulging of tricuspid valve during right ventricular contraction; x = atrial relaxation; v = continued inflow of venous blood; y = passive emptying of right atrium after tricuspid valve opening; Also, Review visual of curve

Question 23

Most likely cause & dx: 74 yo male with htn and DM, compliant with meds and can tolerate moderate level of physical activity, base of heart auscultation reveals crescendo-decrescendo holosystolic murmur

Answer 23

Aortic stenosis; Most commonly due degenerative (senile) calcinosis of aortic leaflets