Ccrn Cardiac Review

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

Conducts electrical impulses from atria to ventricles. Located on R side of intraaterial septum Intrinsic rate of 40-60

Conduxts electrical impulses in the ventricles. contains L and R bundle branches. they have and intrinsic rate of 40-60

The time during which the myocardium cant respond to to even a strong stimulus

The perios in which the chambers of the heart relax

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

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.

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.

Increasing output by increasing preload. It affexts contractility along with SNS. sympatohmimetic and adrenergic meds can affect contractility.

Meds:Milrinone, Digitoxin, Digoxin, Dobutamine, Dopamine, Epinephrine, Isoproterenol. Conditions: decreased vascular resistance, hyperthermia, hypervolemia and early stages of septic shock.

Meds: Atenolol, Metoprolol, Nadolol, Propranolol, Timolol Conditions: heart failure, hypovolemia, incr. vascular resistance, PE, MI, late septic shock Hyperinflation of lungs: CPAP, vent, PEEP

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

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.

Loud S2 Aoric sysotlic murmur

S2 loud and split with inhalation Pulmonic valve murmurs