Cardiology Flashcards
Right dominant configuration of the heart
SA and AV nodes supplied by RCA. RCA supplies inferior portion of LV via PD artery (most common. In left dominant the PD arises from the CFX)
Fick equation
CO = (rate of O2 consumption) / (arterial O2 content - venous O2 content)
What is the pulse pressure proportional to?
Stroke Volume
Name a classic venodilator and a classic vasodilator
Veno - nitroglycerin, Vaso - hydralazine
How does nitroglycerin help in angina?
Venodilation, decreased preload, decreased cardiac work, decreased demand for O2
Normal ejection fraction
Greater than or equal to 55 percent
Causes of increased blood viscosity (3)
Polycythemia, hyperproteinemic states (eg multiple myeloma), hereditary spherocytosis
Cardiac function curves - give the curve affected (CO or venous return) and direction the intersection moves in each of the following: pos inotropy, neg inotropy, inc blood vol, dec blood vol
Positive inotropy - CO, intersection moves up and left. Neg inotropy - CO, intersection moves down and right. Inc BV - venous return, intersection moves up and right. Dec BV - venous return, int moves down and left
On a cardiac cycle graph, the slope of what curve gives contractility?
A line from the origin to the top left portion (where aortic valve closes) of the curve
What causes an S3
Increased filling pressure (e.g. MR, CHF) and dilated ventricles. Normal in children and preggers
What causes an S4?
High atrial pressure. Due to ventricular hypertrophy and stiffness
What is going on in the right heart during each of the following: a wave, c wave, x descent, v wave, y descent
A wave - atrial contraction, c wave - RV contraction, x descent - atrial relaxation, v wave - RA filling, y descent - blood flow from RA to RV
What disorders lead to wide splitting of A2 and P2?
Pulmonic stenosis, RBBB
What condition leads to fixed splitting
ASD
What conditions lead to paradoxical splitting?
Aortic stenosis, LBBB
What kind of murmurs can be heard in an ASD?
Pulmonary flow murmur (inc flow through pul valve), and diastolic rumble (inc flow across tricuspid)
Between inspiration and expiration, which increases right heart findings and which increases left?
Inspiration increases right heart sounds, expiration increases left
What murmurs are louder on hand grip?
MR and VSD
What murmurs are louder on valsalva (decreased venous return)
MVP, HOCM. (most murmurs are quieter on valsalva)
Pulse associated with AS
Parvus and tardus
Murmur associated with VSD
Holosystolic, harsh sounding. Loudest at tricuspid area
Two common causes of PDA
Congenital rubella and prematurity
Give the main ions flowing across the cardiac ventricular muscle membrane during each of the phases of the cycle
Phase 0 - Na, Phase 1 - K starts, Na stops, Phase 2 - Ca, K, Phase 3 - K, Phase 4 - K
Why do CCBs work on heart but not on skeletal muscle?
Skeletal muscle has no dependence on extracellular calcium during an action potential (due to sarcoplasmic stores) unlike cardiac muscle