Cardiovascular Review Flashcards
What is the formula for Cardiac Output?
CO= HR+SV (Heart rate plus Stroke Volume)
What is cardiac output? What is the normal range?
Amount of blood pumped by the heart per minute. 4-8 L/min. The same as normal lung minute volume.
What is cardiac index (CI)?
Assessment of the cardiac output value based on the patient’s size (BSA).
How do you calculate cardiac index? What is the range?
Divide cardiac output by patient’s BSA. 2.5 - 5 L/min
What is stroke volume?
Amount of blood ejected from ventricle with each heart beat. This is affected by preload, contractility and afterload.
What is preload?
Blood remaining after the end of diastolic.
The load that stretches cardiac tissue before each contraction. The amount of blood returned to the right heart from the body and the amount of blood returned to the left heart from the lungs.
What is contractility?
The ability of the heart to contract. Frank-Starling Law states that the stroke volume of the heart increases with response to increase in the volume of blood filling the heart.
What is Afterload?
The force of vascular resistance in relation to ventricular contraction.
(The pressure/resistance is pushed out against (SVR)
What is the difference between right and left heart afterload?
The right heart afterload is affected by pulmonary arteries (PVR) and the left heart after load is affected by systemic vascular resistance (SVR)
What is Pulmonary vascular resistance and the normal value?
Measures the afterload of right heart. 50-250 dynes
What are some examples that will increase PVR?
Acidosis, hypercapnia, hypoxia, COPD, atelectasis, ARDS
What are some examples that would decrease PVR?
Alkalosis, hypocapnia, vasodilating drugs
What is Systemic Vascular resistance (SVR) and the normal value?
Measures afterload of the left hear. 800-1200 dynes
What are some examples of increased SVR?
Hypothermia, hypovolemic shock, decreased cardiac output
What are some examples of decreased SVR?
Anaphylaxis, neurogenic (distributive) shock, spinal shock, septic shock, vasodilating drugs.
Facts about S1 heart sound.
Is the “lub” sound
Hear on systole
Bicuspid/tricuspid valve closure.
Facts about S2 heart sound.
The “dub” sound you hear
Heard on diastolic
Aortic/pulmonic valve closure
What are abnormal heart sounds?
S3 “Kentucky” and S4 “Tennessee”
What is the heart sound S3 indicative of?
Excess filling of the ventricles over filling of the left ventricle.
What are common causes of S3 heart sound?
CHF, chordae tendineae (heart string) dysfunction. CHF is the most common cause.
What is the heart sound S4 indicative of?
Myocardial Infarction
Blood being forced into a stiff (non-compliant) ventricle.
What are some common causes of S4?
Hypertrophic cardiomyopathy, hypertension, pulmonary or aortic stenosis.
What are the auscultation points for heart sounds?
(All, Physicians, Take, Money)
Aortic, Pulmonic, Tricuspid, Mitral
What does sodium do when it comes to the heart?
Flows into the cell to initiate depolarization
What does potassium do when it comes to the heart?
Flows out of our cell to initiate repolarization.
What does Hyperkalemia and Hypokalemia do to the heart?
Hypokalemia causes increases cardiac irritability
Hyperkalemia causes decreased conduction (Sin wave)
What does calcium do when it comes to the heart?
Maintains depolarization of pacemaker cells/myocardial contractility
What does hypocalcemia and hypercalcemia do in the heart?
Hypocalcemia causes decreased contractility and increased irritability.
Hypercalcemia causes increased contractility.
What does magnesium do when it comes to the heart?
Stabilizes the cell membrane.
What does hypomagnesemia and hypermagnesemia do in the heart?
Hypomagnesemia caused decreased conduction.
Hypermagnesemia causes increased myocardial irritability.
What does the right coronary Artery (RCA) do?
Supplies the right ventricle and in most of the population the SA node.
Involved in Inferior STEMI
What does the Posterior Descending Artery (PDA) do?
A branch off the RCA for most populations
Ventricular Septum
Papillary Muscles (heart strings)
What does the Left coronary Artery (LCA) do?
Supplies blood to the left side of the heart
Often called the Left main Artery.
A complete block of the LCA is called the “Widow Maker”
A complete block would be seen in V3, V4, V5, and V6
What does the Left anterior Descending Artery (LAD) do?
Supplies the anterior left ventricle and anterior septum.
Anterior, Septal, and Antero-septal MI
V3 and V4
What does the Left Circumflex Artery (LCX) do?
Supplies lateral/posterior left ventricle
Lateral and posterior MI
V5 and V6
On a cardiac panel, which enzyme is the most sensitive?
Myoglobin
On a cardiac panel, which enzyme is the most specific to cardiac tissue death?
Troponin