W8: Cardio Mgmt & Hemodynamic Flashcards
Heart Rate x Stroke Volume =
Cardiac Output
What is preload?
Volume of blood in ventricles at end of diastole (end of diastolic pressure)
How do we increase preload?
administration of IV fluid - will drip fluids into the venous system and will increase blood volume returning to the heart
sympathetic nervous system - stimulating with a vasopressor - will increase venous return to the heart
What is afterload?
Resistance left ventricle must overcome to circulate blood
What is afterload increased in?
Hypertension
Vasoconstriction
Increased afterload results in
Increased cardiac workload
What is the resistance the heart has to pump against?
Afterload is the force or load against which the heart has to contract to eject the blood
How does tachycardia impact cardiac output and coronary artery filling?
Tachycardia of atrial or ventricular origin reduces stroke volume and cardiac output, particularly when the ventricular rate is greater than 160 beats/min.
Frank Starling Principle
The Frank-Starling Law states that the stroke volume of the left ventricle will increase as the left ventricular volume increases due to the myocyte stretch causing a more forceful systolic contraction.
Intrinsic rate
The patients own heart beat
Extrinsic rate
A rate that is set by an artificial source
Temporary Pacemakers Indications
Dysrhythmias that are unresponsive to drug therapy and that compromise hemodynamic status
Usual application symptomatic bradycardia or progressive heart block secondary to ACS or drug toxicity
When are temporary pacemakers used?
Usual application symptomatic bradycardia or progressive heart block secondary to ACS or drug toxicity
What do temporary pacemakers require?
Requires pulse generator and pacing leads
Synchronous pacing modes (demand) pacers
DDD
VVI
Describe DDD Pacing
most physiologic- enhances atrial contribution to ventricular filling
Describe VVI Pacing
designed to pace ventricle; demand pacing; used in atrial fibrillation
Asynchronous Pacer
Emergency DOO
Describe DOO Pacer
Emergency DOO (both atrium and ventricles) or VOO(ventricles) used is asystole or operating room if EMI(electric magnet interference) is an issue
Ventricular pacing
–Ventricular pacing spikes followed by wide, bizarre QRS complexes
A-V Pacing
Atrial & Ventricular pacing spikes followed by atrial & ventricular complexes
Modes of Pacing
Atrial pacing
*Intact AV node conduction system required
Ventricular pacing
•Loss of atrial kic
Patient Education - Temporary Pacer
➢Exposed lead wires
➢Soiled or dislodged dressings
➢Electrical devices from home
➢Movement of affected extremity
Patient Education - Permanent
➢Remote monitoring can be transtelephonic or Internet-based-status of the pacemaker will be regularly checked or “interrogated”
➢Avoiding electromagnetic interference
➢Activity
➢Pacemaker ID card
What is an ICD?
The implantable cardioverter defibrillator (ICD) system
Describe ( Implantable Cardioverter-Defibrillator) ICD
●Electronic device used in treatment of life-threatening tachy dysrhythmias and:
●Sudden cardiac arrest
●Spontaneous sustained VT
●Familial or inherited condition (long QT syndrome)
●Recurrent syncope of undetermined etiology
●Capable of identifying and terminating lethal ventricular arrhythmias