Ccrn Cardiac Review

Cardiac infor matin fo

25 cards   |   Total Attempts: 184
  

Cards In This Set

Front Back
Explain the SA node
It is the pacemaker of the heart located in the upper portion of the heart. It has an intrinsic rate of 60-100 beats/min
What is the atrioventricular node?
Conducts electrical impulses from atria to ventricles. Located on R side of intraaterial septum Intrinsic rate of 40-60
What is bundle of HIS
Conduxts electrical impulses in the ventricles. contains L and R bundle branches. they have and intrinsic rate of 40-60
What is the refractory period?
The time during which the myocardium cant respond to to even a strong stimulus
What is diastole?
The perios in which the chambers of the heart relax
What is systole?
Ejection or the period in which the chambers of the heart contract. Begins when the ventricles fill with blood. the end of the ejection phase is reflected by the dicrotic notch on the aline
What is pre load?
It is the volume of blood in the left ventricle and the ability of the ventricle to stretch at the end of diastole. It is measured my RAWP on the L side of the heart and CVP orRAP on the right side of the heart. Venous return, total blood volume,and atrial kick affect the volume aspect. stiffness and thickness of cardiac muscle affect compliance of the ventricle. It is enhanced through volume admin. of crytalloid, collloid, plasma expanders or blood products. Its decreased through diuretics or vasodilators.
What is afterload?
It is ventricular wall tension or stress during systolic ejection(stretching ability). Measured by SVR in L side and PVR in R side.It is increased by factors that oppose stretching like arteriosclerotic disease, hypervolemia and aortic stenosis. It is decreased by the correction of low preload od with vasodilating agents such as ACE inhibitors, NTP, and morphine. It is increased with vasopressors dopa, levo, and epi.
What is the Starling mechanism?
Increasing output by increasing preload. It affexts contractility along with SNS. sympatohmimetic and adrenergic meds can affect contractility.
Factors that increase cardiac workload
Meds:Milrinone, Digitoxin, Digoxin, Dobutamine, Dopamine, Epinephrine, Isoproterenol. Conditions: decreased vascular resistance, hyperthermia, hypervolemia and early stages of septic shock.
Factors that decrease cardiac workload.
Meds: Atenolol, Metoprolol, Nadolol, Propranolol, Timolol Conditions: heart failure, hypovolemia, incr. vascular resistance, PE, MI, late septic shock Hyperinflation of lungs: CPAP, vent, PEEP
Heart rate
Parasympathetic and sympathetic nervous system. Parasympathetic fibers in vagus nerve located neas SA and AV conduction can cause bradycardia. Sympathetic fibers parallel the coronary circulation and cause fight or flight response
Baroreceptors and chemoreceptors
Located in carotid sinus and aortic arch and sense presseure changes and active ans to raise or lower HR Chemoreceptors are in bifurication of aortic arch sense changes in O2, pH, and CO2 they trigger increases in resp. rate and depth.
Heart tones near aortic area
Loud S2 Aoric sysotlic murmur
Heart tones near pulmonic area
S2 loud and split with inhalation Pulmonic valve murmurs