Cardiac Flashcards
Bainbridge reflex
Also called atrial reflex-
Reflex tachycardia in response to increased CVP+ stretch of Right atrial receptors and helps equalize pressures in both sides
How to calculate cardiac output (CO)
HR×SV
Heart rate × stroke volume
How to calculate Cardiac index?
Cardiac output ÷ BSA = CI in L/min/m2
Calculate mean arterial pressure
SBP+ 2(DBP)/3
Add Systolic BP to 2 times the diastolic BP and divide by 3
Diastolic BP is 2/3 of cardiac cycle. Immediately at birth it’s 1/2 of the cardiac cycle
What is the PAOP and normal values?
when the balloon of a pulmonary artery catheter is inflated, the turbulence behind the balloon is blocked and you get the Pulmonary artery occlusive pressure (used to be pulmonary artery wedge pressure) and sometimes is called pulmonary capillary wedge pressure
PAOP represents pressures in the left side of the heart and pulmonary filling pressures, pulmonary vascular bed
normal value should be 5-12 mmHg
What is endocardial cushion defect?
also called
-atrioventricular canal (AV canal or AVC)
-atrioventricular septal defect (AVSD)
1.) ASD
2. VSD
3.) improperly formed mitral and/or tricuspid valves.
specifically the left sided (mitral valve) has three cusps rather than the two cusps that normally form the valve (one of the normal cusps is divided into two : this is called a cleft or a cut in the mitral valve causing regurgitation.
1/3 of all children born with av canal defect also have down syndrome
SVR
the mean pressure difference in the systemic vascular bed divided by blood flow. It indicates the resistance the left ventricle must pump against
What do large A waves indicate on the PAOP tracing?
large A waves may be seen with increased pressure during atrial contraction. This could be caused by mitral stenosis, an ischemic left ventricle or a failure of a left ventricle.
Hill’s sign
a popliteal blood pressure that is at least 20 mmHg higher than the brachial blood pressure can be a sign of aortic insufficiency
what is pulsus alternans
the pulses alternate between strong and weak
- -most commonly seen in left ventricular failure when the weakened myocardium cant maintain an even pressure w/ each contraction
- -also seen in CHF
medication for sustained SVT or supraventricular tachycardia
0.1 mg/kg adenosine (rapid IV)
if not effective increase to 0.2mg/kg
MOA: slows conduction time through the AV node, interrupting the re-entry pathways through the AV node, restoring NSR.
–used to suppress or eliminate SVT, also used in diagnostic studies to establish the cause of SVT
adverse effects of Adenosine
transient arrhythmias, flushing, dyspnea and (rarely)apnea
in 30% of patients SVT recurs
which part of the electrocardiogram represents ventricular depolarization?
the QRS complex represents ventricular depolarization
on the ECG the T wave represents…..
ventricular repolarization
Bigeminy
a PVC occurring every other beat
