EKG strips SG - Summary Medical-Surgical Nursing

Ventricular Fibrillation A severe derangement of the heart rhythm characterized on ECG by irregular waveforms of varying shapes and amplitude, with no effective contraction, resulting in no CO. VF is a lethal dysrhythmia. The HR is not measurable, rhythm is irregular and chaotic. The P wave is not visible, and the PR interval and the QRS interval are not measurable. Tx: immediate CPR, use of defibrillation and drug therapy. A run of 3 or more premature ventricular contractions. It occurs when an ectopic foci fires repetitively and the ventricle takes control as the pacemaker. The development of VT is an ominous sign. It is a life threatening dysrhythmia because of ↓ CO. Ventricular rate is 150-250 bpm. rhythm may be regular or irregular. P waves occur independently of the QRS but are buried and aren't measurable. The QRS complex is distorted and duration is ≤ 0.12 sec. Tx: o Hemodynamically stable: IV procainamide, sotalol, amiodarone, or lidocaine is used. o Hemodynamically unstable: IV amiodarone or lidocaine is given followed by cardioversion PSVT – Atrial Tachycardia A dysrhythmia originating in an ectopic focus anywhere above the bifurcation of the bundle of His. The HR is 150-220 bpm and the rhythm is regular or slightly irregular. The P wave is often hidden in the preceding T wave but if seen it may have an abnormal shape. The PR interval may be shortened or normal and the QRS complex is usually normal. Tx: Assessment of hemodynamic status, drug therapy includes BB, procainamide, amiodarone, or lidocaine. First Degree AV Block The first degree block is when every impulse is conducted to the ventricles but the duration of AV conduction is prolonged. Tx: no treatment for 1st degree block Second Degree AV Block The atrial rate is normal, but ventricular rate may be slower because of nonconducted or blocked QRS complexes resulting in bradycardia. Once a ventricular beat is blocked, the cycle repeats itself with progressive lengthening of the PR intervals until another QRS complex is blocked. The rhythm appears on the ECG in a pattern of grouped beats. Ventricular rhythm is irregular, the p wave has a normal shape, the QRS complex has a normal shape and duration. Tx: o Symptomatic pt: atropine is used to ↑ HR, or temporary pacemaker may be needed. o Asymptomatic: rhythm is closely observed with transcutaneous pacemaker. Third Degree AV Block Atrial rate is usually a sinus rate of 60-100bpm, the ventricular rate depends on the site of the block, in the AV node, the rate is 40-60bpm, if in the His-purkinje system it is 20-40 bpm. A and V rhythms are regular but unrelated to each other. The P wave has a normal shape, the PR interval is variable, and there is not time relationship between the P and the QRS complex. Tx: o Symptomatic - Pacemaker. The use of drugs such as atropine, epinephrine, isoproterenol, and dopamine is a temp measure to ↑ HR and support BP. If is a result of CCB toxicity, calcium chloride may be indicated. Calcium Channel Blockers "ine" - Amlodipine, felodipine, nifedipine, nicardipine or diltiazem (Cardizem) or verapamil (Calan, Isoptin) Prevents calcium entry into vascular smooth muscle cells and myocytes (cardiac cells) Coronary and peripheral vasodilation Reduces hear rate, contractility, and blood pressure Beta Blockers "Lol" - Atenolol, carvedilol (Coreg), Metoprolol (Lopressor) Inhibit sympathetic nervous stimulation of the heart Reduce heart rate, contractility, and blood pressure o Decreases afterload. Decreases SA automaticity ARB's (Angiotensin Receptor Blockers) sartan....Losartan (Cozaar) Inhibit binding of angiotensin II AT receptors resulting in vasodilation Used for patients intolerant of ACE Inhibitors ACE Inhibitors (Angiotensin Converting Enzyme) Pril's...Ace is the prilace of the helpful hardware man: Catopril (Capoten), Enalapril (Vasotec) Prevents conversion of angiotensin I to angiotensin II resulting in vasodilation. ↓ endothelial dysfunction Useful w/heart failure, tachycardia, MI, htn, diabetes, and chronic kidney disease Cardiac Output HR x Stroke volume = CO Cardiac output is the amount of blood pumped by each ventricle in 1 minute. The normal adult at rest is 4-8L/min. Preload The volume of blood in the ventricles at the end of diastole, before the next contraction. CVP - measured in the rt. atrium, is the rt. ventricular preload or rt. ventricular end diastolic pressure when there is not tricuspid valve dysfunction, intracardiac defect or dysrhythmia. Afterload Peripheral resistance against which the left ventricle must pump. Affected by the size of the ventricle, wall tension and arterial blood pressure. If the arterial BP is ↑, the ventricles will meet increased resistance to eject blood, ↑ work demand. SVR (systemic vascular resistance)- resistance of the systemic vascular bed. Contractility Describes the strength of contraction. Contractility improving drugs Epinephrine, norepinephrine (Levophed) isoproterenol (Isuprel), dopamine (Intropin), dobutamine (Dobutrex), digitalis, calcium and milrinone Contractility reducing drugs Epinephrine, norepinephrine (Levophed) isoproterenol (Isuprel), dopamine (Intropin), dobutamine (Dobutrex), digitalis, calcium and milrinone S3 A low intensity vibration of the ventricular walls usually associated with ↓ compliance of the ventricles during filling. Heard best at the apex of the heart. (ventricular gallop, ken(s1)...tuck(s2)..y(s3)) Caused by rapid ventricular filling, and may occur with ventricular dysfunction, excessively rapid early diastolic ventricular filling and restrictive myocardial or pericardial diseases. Often indicates CHF and fluid overload. S4 A low frequency vibration caused by atrial contraction. heard best at the mitral or tricuspid areas, atrial gallop...Ten (S4)...nes(S1)...see (S2) Seen in conditions that ↑ the resistance to filling (MI, CAD, CHF and cardiomyopathy) or in conditions that result in systolic overload (HTN, aortic stenosis, and hyperthyroidism). Echocardiogram An echo uses ultrasound waves to record the movement of the structures of the heart. It provides info about abnormalities of valvular structures and motion, cardiac chamber size and contents, ventricular muscle and septal motion and thickness, pericardial sac, and ascending aorta. The EF or ejection fraction or the percentage of end diastolic blood volume that is ejected during systole can also be measured. Cardiac Catheterization A radiopaque catheter is inserted through an arm (basilica or cephalic) or leg vein (femoral) and advanced to the vena cava, rt. atrium, rt. ventricle, pulmonary artery and then pressures are recorded. It provides information about CAD, coronary spasm, congenital and valvular heart disease, and ventricular function. With inj. of contrast media, the coronary arteries can be visualized, chambers of the heart can be outlined, and wall motion can be observed. EKG Electrocardiogram - basic P, QRS, and T waveforms are used to assess cardiac function. A graphic tracing of the electrical impulses produced in the heart. The waveforms on the ECG represent electrical activity produced by the movement of charged ions across the membranes of myocardial cells representing depolarization and repolarization. Deviations from normal sinus rhythm can indicate abnormalities in heart function. P wave 0.06 - 0.12 Represents the time for the passage of the electrical impulse through the atrium causing atrial depolarization (contraction) should be upright PR interval 0.12 - 0.20 Measured from the beginning of the P wave to beginning of QRS complex  represents time taken for impulse to spread through the atria, AV node and bundle of HIS, the bundle branches and Purkinje fibers, to a point immediately preceding ventricular contraction. QRS interval ≤ 0.12 Measured from beginning to end of QRS complex  represents time take for depolarization (contraction) of both ventricles (systole) ST segment 0.12 Measured from the S wave to the beginning of the T wave  represents the time between ventricular depolarization and repolarization (diastole); should be flat T wave 0.16 Represents time for ventricular repolarization; should be upright QT interval 0.34 - 0.43 Measured from beginning of QRS complex to end of T wave  represents time taken for entire electrical depolarization and repolarization of the ventricles. Sinus Bradycardia HR is ≤ 60 bpm and the rhythm is regular. Tx: administration of atropine, pacemaker, or if the client is having bradycardia due to drugs, d/c the drug. Sinus Tachycardia HR is 101-200 bpm and the rhythm is regular Tx: treat underlying cause, treating pain, hypovolemia, vagal maneuvers can be attempted, Beta blockers (metoprolol {Lopressor) can be given to ↓ HR and ↓ myocardial oxygen consumption. Sinus rhythm Normal sinus rhythm refers to a rhythm that originates in the SA node at a rate of 60-100 times per minute and follows the normal conduction pattern of the cardiac cycle. Atrial Flutter An atrial tachydysrhythmia identified by recurring, regular, saw tooth shaped flutter waves that originate from a single ectopic focus in the rt. atrium or left atrium. Tx: slow the atrial flutter/ventricular response by ↑ AV block. o Drugs used to control ventricular rate include calcium channel blockers and Beta blockers. o Electrical cardioversion may be performed to convert the atrial flutter to sinus rhythm in an emergency. o Antidysrhythmia drugs used to convert atrial flutter to sinus rhythm or to maintain sinus rhythm include amiodarone, propafenone, ibutilide and flecainide. o Radiofrequency catheter ablation is the treatment of choice for atrial flutter.