Cardiac Anatomy & Physiology
This conduction tissue has the fastest conduction velocity.
What are the Purkinje fibers?
These vasodilators donate NO → ↑cGMP and primarily decrease preload to relieve angina.
What are nitrates?
A holosystolic murmur best heard at the apex, radiating to the axilla.
What is mitral regurgitation?
What blood test is commonly used to detect myocardial injury
Cardiac troponin
An irregularly irregular rhythm with no distinct P waves.
What is atrial fibrillation?
A low-frequency heart sound in early diastole associated with volume overload and CHF.
What is S3?
Clue: Selective β₁-blockers reduce myocardial O₂ demand by lowering these two parameters.
What are heart rate and contractility?
A subacute endocarditis organism classically associated with dental procedures.
What is viridans streptococcus?
On chest X-ray, cardiomegaly is diagnosed when the cardiothoracic ratio exceeds what percentage?
What is 50%.
In the standard limb leads, which lead normally shows the tallest positive R wave because it is most aligned with the heart’s electrical axis?
What is lead II?
This phase of the SA node action potential is due to slow Na⁺ influx through “funny” channels.
What is phase 4?
This antiarrhythmic class blocks K⁺ channels, prolongs repolarization, and can prolong QT.
What is Class III?
Hypotension, JVD, muffled heart sounds and pulsus paradoxus indicate this emergency.
What is cardiac tamponade?
Which nuclear medicine technique is considered the non-invasive reference standard for measuring coronary flow reserve in absolute mL/min/g?
What is PET myocardial perfusion imaging?
For an inferior ST-elevation myocardial infarction (STEMI), you will see ST elevation in these three leads.
What are leads II, III, and aVF?
The normal splitting of S2 becomes fixed (unaffected by respiration) in this congenital heart defect.
What is an atrial septal defect (ASD)?
These lipid-lowering drugs inhibit HMG-CoA reductase, upregulating hepatic LDL receptors.
What are statins?
A continuous “machine-like” murmur from a persistent left-to-right ductus arteriosus.
What is patent ductus arteriosus (PDA)?
In an echocardiogram, this is considered NORMAL range for a left ventricular ejection fraction.
What is 55% to 70%?
A regularly irregular pattern with grouped beating on ECG is typical of this type of atrioventricular block.
What is second-degree AV block, Mobitz type I (Wenckebach)?
Inspiration increases venous return and delays pulmonic valve closure, producing this physiologic finding.
What is physiologic splitting of S2?
This Class IB anti-arrhythmic is used post-MI because it preferentially targets ischemic ventricular tissue.
What is lidocaine?
Early cyanosis, RV outflow obstruction, RV hypertrophy, VSD, and an overriding aorta describe this congenital defect.
What is Tetralogy of Fallot?
In an echocardiogram, this is considered mildly reduced range for a left ventricular ejection fraction.
What is 41% to 49%?
The combination of a short PR interval and a delta wave (slurred upstroke of the QRS) is the classic ECG sign of this syndrome.
What is Wolff-Parkinson-White (WPW) syndrome?