Cardiac System Med Surg Notes 1

CARDIAC OUTPUT (CO) Total volume pumped per minute Normal 4 - 8 L/min • Lungs sound wet due to backflow • Shortness of breath • Skin will be cold & clammy CO = HR x Stroke Volume Cardiac Output • Weak peripheral pulses Heart Rate STROKE VOLUME CONTRACTILITY EJECTION FRACTION (EF) Amount of blood pumped out of the ventricle with each beat or contraction Force / strength of contraction of the heart muscle % of blood expelled from the left ventricle with every contraction Normal EF: 50 - 70% 55% of what’s inside of the left ventricle PRELOAD AFTERLOAD Amount of blood retune the right side of the hea the end of diastole that the left ventricle has to pump against ance it must overcome to circulate blood) ly measured by systolic blood pressure! Hemodynamic Parameters Total volume pumped per minute Normal 4 - 8 L/min Cardiac output per body surface area CI = CO surface area 2.5 – 4.0 L/min/m2 Pressure in the superior vena cava. Shows how much pressure from the blood is returned to the right atrium from the superior vena cava. 2 – 8 mmHg Average pressure in the systemic circulation (your body) through the cardiac cycle 70 – 100 mmHg The resistance it takes to push blood through the circulatory system to create blood flow 800 – 1200 dynes/sec/cm blood from the body back to the right side of the heart from the lungs 1. Superior / Inferior Vena Cava 7. Pulmonary Vein 2. Right Atrium 8. Left Atrium 3. Tricuspid Valve 9. Bicuspid / Mitral Valve 4. Right Ventricle 10. Left Ventricle 5. Pulmonic Valve 11. Aortic Valve 12. Aorta Deoxygenated blood to the lungs Oxygenated blood to the body VEINS - Carry deoxgenated blood back to the heart A Big Bounding Pulse AV Node Bundle of His Bundle Branches Purkinje Fibers TIP S1 NORMAL LUB Think M for Midclavicular & Mitral has 5 letters for "5th intercostal space" Tricuspid & mitral valve closure Closing of the valves Valve opening does not normally produce a sound S2 DUB S3 Early Diastole in rapid ventricle filling ABNORMAL Abnormal ventricular filling Extra q sounds S4 (forcing blood into a stiff ventricle) SYSTOLE: Ventricle pump / ejection = LUB (S1) ry Memo Trick CO (contract) ZY (systole) RE (relax) D (diastole) P QRS Atrial contraction (squeeze) DE-polarization DE-compressing Ventricle contraction (squeeze) DE-polarization P DE-compressing T Ventricles RE-laxing RE-polarizing RE-filling with blood PR INTERVAL QRS ST SEGMENT QT INTERVAL Time between ventricular deMovement of electrical activity from atria to ventricles polarization and repolarization (ventricular contraction) la v rl ll Time take from ventricles to depolarize, contract, and repolarize NORMAL SINUS 60 - 100 bpm SINUS TACHYCARDIA > 100 bpm SINUS BRADYCARDIA < 60 bpm • Should be present & upright • Comes before QRS complex • One P wave for every QRS complex 1 sec. Normal PR interval: 0.12 - 0.2 seconds Normal QRS complex: 0.06 - 012 followed by a QRS complex? 0.04 sec. • Should not be widened or shortened W iden is ofte – this may indicate problems! seen in PV n C’s C’s,, Electrolyte imbalances & drug toxic ity! 0.20 sec. 5 large boxes = 1 second 1 small box = 0.04 seconds • Regular or irregular? 6 SECOND METHOD Be sure and chec k that the strip is 6 Count th seconds! e boxes the 6 second strips & multiply by 10 BIG BOX METHOD 300 divided by the number of big boxes between 2 R’s 1 2 3 4 5 6 R’s X 10 = 60 beats per minutes 300 / 5 = 60 BPM RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX 60 - 100 bpm Regular Upright & uniform before each QRS Normal R Normal T P QS SINUS BRADY The sinus node creates an impulse KEY at a slower-than-normal rate RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX < 60 bpm Regular Upright & uniform before each QRS Normal Normal CAUSES TREATMENT q Lower metabolic needs • Sleep, athletic training, hypothyroidism q Vagal stimulation q Medications • Calcium channel blockers, beta blockers, Amiodarone q Correct the underlying cause! SINUS TACHY The sinus node creates an impulse KEY at a faster-than-normal rate RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX > 100 bpm Regular Upright & uniform before each QRS Normal Normal CAUSES TREATMENT q Physiologic or psychological stress • Blood loss, fever, exercise, dehydration q Identify the underlying cause! q Certain medications • Stimulants - caffeine, nicotine • Illict drugs - cocaine, amphetamines • Stimulate sympathetic response - epinephrine q Heart failure q Cardiac tamponade q Hyperthyroidism ck: Memory tri looks like tombstones RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX 100 - 250 bpm Regular Not visible None Wide (like tombstones) > 0.12 seconds Irregular, coarse waveforms of different shapes. The ventricles are quivering and there is no contractions or cardiac output which may be fatal! CAUSES MANIFESTATIONS q Myocardial ischemia / infarction q Patient is usually awake (unlike V-fib) q Electrolyte imbalances q Digoxin toxicity q Chest pain q Lethargy q Stimulants: caffeine & methamphetamines q Anxiety q Syncope q Palpitations No Cardi ac Outpu t = Low Oxy gen TREATMENT UNSTABLE CLIENTS WITHOUT A PULSE STABLE CLIENT WITH A PULSE q Oxygen q Antidysrhythmics (ex. Amiodarone...stabilizes the rhythm) q Synchronized Cardioversion q CPR q Follow ACLS protocol for defibrillation q Possible intubation q Drug therapy • Synchronized administration of shock (delivery in sync with the QRS wave). • Epinephrine, vasopressin, amiodarone • Cardioversion is NOT defibrillation! (defibrillation is only given with deadly rhythms!) UNTREATED VT CAN LEAD TO ↓ VENTRICULAR FIBRILLATION ↓ DEATH SHOCK! RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX Rapid, disorganized pattern of electrical activity in the ventricle in which electrical impulses arise from many different foci! Unknown Chaotic & irregular Not visible Not visible Not visible CAUSES MANIFESTATIONS q Cardiac injury q Loss of consciousness q Medication toxicity q May not have a pulse or blood pressure q Electrolyte imbalances q Respirations have stopped q Untreated ventricular tachycardia q Cardiac arrest & death! No Card Outputiac = no Oxyg en to the bo dy TREATMENT q CPR q Drug Therapy • Vasoconstriction: Epinephrine q Oxygen q Defib (follow ACLS protocol for defibrillation) • Antiarrhythmic: Amoidaraon, lidocaine • Possibly magnesium q Possible intubation TIP “Defib the Vfib” Cardioversion vs. Defibrillation CARDIOVERSION DEFIBRILLATION q Synchronized shock q Asynchronous q Lower amount of energy q Higher amount of energy q Not done with CPR q Resume CPR after shock q Stable clients q Unstable clients q Ex. A-fib q Example: pulseless VT or VF KEY irregular r-r intervals ↓↓ ↓ ↓ ↓ RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX Usually over 100 BPM Irregular None. They are irregular (fibrillary waves) Visible Normal Uncoordinated electrical activity in the atria that causes rapid & disorganized “fibbing” of the muscles in the atrium. The atria is quiverin g! CAUSES MANIFESTATIONS q Open heart surgery q Most commonly asymptomatic q Heart failure q Fatigue q COPD q Malaise q Hypertension q Dizziness q Ischemic heart disease q Shortness of breath q Tachycardia All due to low 02 q Anxiety q Palpitations TREATMENT STABLE PT. UNSTABLE PT. q Oxygen q Oxygen q Drug therapy! q Cardioversion • Beta blockers • Calcium channel blockers • Synchronized administration of shock (delivery in sync with the QRS wave). • Cardioversion is NOT defibrillation! • Digoxin • Amiodarone ! • Anticoagulant therapy to prevent clots ! Risk for clots! The atria quiver causes pooling of blood in the heart which increases the risk for clots = increased risk for MI, PE, CVA’s, & DVTs! defibrillation Defibrillation is only given with deadly rhythms! RATE Depends on the underlying rhythm RHYTHM Regular but interrupted due to early P waves P WAVE Visible but depends on timing of PVC (may be hidden) PVC PR INTERVAL Slower than normal but still 0.12 - 0.20 seconds QRS COMPLEX Sharp, bizarre, and abnormal during the PVC Early “premature” conduction of a QRS complex BIGEMINY: every other beat TRIGEMINY: every 3rd beat QUADRAGEMINY: every 4th beat CAUSES q Heart failure q Myocardial ischemia / infarction q Drug toxicity q Caffeine, tobacco, alcohol q Stress or Pain Exercise Fever Hypervolemia Heart failure Tachycardia R-ON-T PHENOMENON: PVC arises spontaneously from the repolarization gradient (T-wave) may precipitate V-fib q Increased workload on the heart TREATMENT MANIFESTATIONS q May be asymptomatic *TX based on underlying cause* q May not be harmful if the client has a healthy heart q Oxygen q Decrease caffeine intake q Correct the electrolyte imbalances q Feels like your heart... • “Skipped a beat” • “Hea q Chest pain q D/C or adjust the drug causing toxicity q Decrease stress or pain Chest pain fy the healthcare provider if the client complains of chest pain, if the PVC’s increase in frequency or if the PVC’s occur on the T wave (R-on-T phenomenon). AYSTOLE RATE RHYTHM P WAVE PR INTERVAL QRS COMPLEX CAUSES TREATMENT q Myocardial ischemia/infarction q High quality CPR q Heart failure q Electrolyte imbalances (common: hypo/hyperkalemia) q Severe acidosis q Cardiac tamponade q Cocaine overdose ! Flatline • Heel of hand on the center of the chest • Arms straights • Shoulders aligned over hands • Compress at 2 - 2.4 inches at a rate of 100 - 120 min • 30 compressions to 2 rescue breaths • Minimal interruptions