CARDIAC DYSRHYTHMIAS

PYRAMID POINTS Six-second strip method to determine heart rate Recognizing rhythms and the appropriate treatment measures Normal sinus rhythm Premature ventricular contractions Atrial fibrillation Ventricular tachycardia Ventricular fibrillation Cardioversion and defibrillation procedures Client teaching for pacemakers

SIX-SECOND STRIP METHOD TO DETERMINE HEART RATE Can be used to determine heart rate for both regular and irregular rhythms To determine atrial rate, count the number of P-P intervals in 6 seconds and multiply by 10 to obtain a full-minute rate To determine ventricular rate, count the number of R-R intervals in 6 seconds and multiply by 10 to obtain a full-minute rate For accuracy, timing should begin on the P wave or the QRS complex and end exactly at 30 large blocks later

SIX-SECOND STRIP METHOD TO DETERMINE HEART RATE From Paul, S. & Hebra, J. (1998). The nurse’s guide to cardiac rhythm interpretation. Philadelphia: W.B. Saunders

NORMAL SINUS RHYTHM DESCRIPTION Rhythm originates from the SA node Atrial and ventricular rhythms are regular Atrial and ventricular rates are 60 to 100 beats per minute

NORMAL SINUS RHYTHM From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

SINUS BRADYCARDIA DESCRIPTION Atrial and ventricular rates are below 60 beats per minute Treatment may be necessary if the client is symptomatic Note that a low heart rate may be normal for some individuals

SINUS BRADYCARDIA From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

SINUS BRADYCARDIA IMPLEMENTATION Attempt to determine cause and if a medication is suspected as causing the bradycardia, hold the medication and notify the physician Administer oxygen as prescribed Administer atropine sulfate as prescribed to increase the heart rate to 60 beats per minute

SINUS BRADYCARDIA IMPLEMENTATION Be prepared to apply a noninvasive pacemaker initially as prescribed, if the atropine sulfate does not increase the heart rate sufficiently Avoid additional doses of atropine sulfate because they will induce tachycardia Monitor for hypotension and administer IV fluids as prescribed Depending on the cause of the bradycardia, the client may need a permanent pacemaker

SINUS TACHYCARDIA DESCRIPTION Atrial and ventricular rates are 100 to 180 beats per minute IMPLEMENTATION Identify the cause of the tachycardia Decrease the heart rate to normal by treating the cause

SINUS TACHYCARDIA From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

ATRIAL FIBRILLATION DESCRIPTION Multiple rapid impulses from many foci depolarize in the atria in a totally disorganized manner at a rate of 350 to 600 times per minute The atria quiver, which can lead to the formation of thrombi P wave is absent

ATRIAL FIBRILLATION From Paul, S. & Hebra, J. (1998). The nurse’s guide to cardiac rhythm interpretation. Philadelphia: W.B. Saunders.

ATRIAL FIBRILLATION IMPLEMENTATION Administer oxygen Administer anticoagulants as prescribed because of the risk of emboli Administer cardiac medications as prescribed to control the ventricular rhythm and assist in the maintenance of cardiac output Prepare the client for cardioversion as prescribed Instruct the client in the use of medications as prescribed to control the dysrhythmia

PREMATURE VENTRICULAR CONTRACTIONS (PVCs) DESCRIPTION Early ventricular complexes result from increased irritability of the ventricles PVCs frequently occur in repetitive rhythms such as bigeminy, trigeminy, and quadrigeminy The QRS complexes may be unifocal or multifocal

PREMATURE VENTRICULAR CONTRACTIONS (PVCs) From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

PREMATURE VENTRICULAR CONTRACTIONS (PVCs) IMPLEMENTATION Notify the physician if PVCs are noted Identify the cause and treat based on the cause Evaluate electrolytes, particularly the potassium level, since hypokalemia can cause PVCs Administer oxygen as prescribed

PREMATURE VENTRICULAR CONTRACTIONS (PVCs) IMPLEMENTATION Administer lidocaine as prescribed Notify the physician if the client complains of chest pain, if PVCs increase in frequency, are multifocal, occur on the T wave (R on T), or occur in runs of ventricular tachycardia

VENTRICULAR TACHYCARDIA (VT) DESCRIPTION Occurs when there is a repetitive firing of an irritable ventricular ectopic focus at a rate of 140 to 250 beats per minute or more May present as a paroxysm of three self-limiting beats or more, or may be a sustained rhythm Can cause cardiac arrest

VENTRICULAR TACHYCARDIA (VT) From Paul, S. & Hebra, J. (1998). The nurse’s guide to cardiac rhythm interpretation. Philadelphia: W.B. Saunders.

VENTRICULAR TACHYCARDIA (VT) STABLE CLIENT WITH SUSTAINED VT Administer oxygen as prescribed Administer antidysrhythmics as prescribed

VENTRICULAR TACHYCARDIA (VT) UNSTABLE CLIENT WITH VT Administer oxygen and antidysrhythmic therapy as prescribed Prepare for synchronized cardioversion if unstable Attempt cough cardiopulmonary resuscitation (CPR) by asking the client to cough hard every 1 to 3 seconds PULSELESS CLIENT Defibrillation and cardiopulmonary resuscitation (CPR)

VENTRICULAR FIBRILLATION (VF) DESCRIPTION Impulses from many irritable foci fire in a totally disorganized manner Chaotic rapid rhythm in which the ventricles quiver Rapidly fatal if not successfully terminated within 3 to 5 minutes Client lacks a pulse, blood pressure, respirations, and heart sounds

VENTRICULAR FIBRILLATION (VF) From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

VENTRICULAR FIBRILLATION (VF) IMPLEMENTATION Defibrillate immediately, up to three times consecutively at 200, 300, and 360 joules Initiate CPR Administer oxygen as prescribed Administer epinephrine (Adrenalin) and antidysrhythmic therapy with lidocaine as prescribed Prepare to administer additional prescribed antidysrhythmics

VAGAL MANEUVERS DESCRIPTION Induce vagal stimulation of the cardiac conduction system Used to terminate supraventricular tachydysrhythmias

CAROTID SINUS MASSAGE The physician instructs the client to turn the head away from the side to be massaged The physician massages over the carotid artery for 6 to 8 seconds until there is a change in cardiac rhythm Observe the cardiac monitor for a change in rhythm Record an ECG rhythm strip before, during, and after the procedure Have a defibrillator and resuscitative equipment available Monitor VS, cardiac rhythm, and level of consciousness (LOC) following the procedure

VALSALVA MANEUVERS The physician instructs the client to bear down or induces a gag reflex in the client, both of which stimulate a vagal reflex Monitor the heart rate, rhythm, and BP Observe the cardiac monitor for a change in rhythm; record an ECG rhythm strip before, during, and after the procedure Provide an emesis basin if the gag reflex is stimulated, and initiate precautions to prevent aspiration Have a defibrillator and resuscitative equipment available

CARDIOVERSION DESCRIPTION Synchronized countershock to convert an undesirable rhythm to a stable rhythm An elective procedure performed by the physician A lower amount of energy is used than with defibrillation Defibrillator is synchronized to the client’s R wave to avoid discharging the shock during the vulnerable period (T wave) If the defibrillator were not synchronized, it would discharge on the T wave and cause VF

CARDIOVERSION PREPROCEDURE Obtain consent Administer sedation as prescribed Hold digoxin (Lanoxin) 48 hours preprocedure as prescribed to prevent postcardioversion ventricular irritability

CARDIOVERSION DURING THE PROCEDURE Ensure that the skin is clean and dry in the area where the electrode paddles will be placed Stop the oxygen during the procedure to avoid the hazard of fire Be sure that no one is touching the bed or the client when delivering the countershock

CARDIOVERSION POSTPROCEDURE Maintain airway patency Administer oxygen as prescribed Assess VS Assess LOC Monitor cardiac rhythm Monitor for indications of successful response, such as conversion to sinus rhythm, strong peripheral pulses, and an adequate BP

DEFIBRILLATION DESCRIPTION An asynchronous countershock used to terminate pulseless VT or VF Three rapid, consecutive shocks are delivered with the first at an energy of 200 joules If unsuccessful, the shock is repeated at 200 to 300 joules The third and subsequent shock will be at 360 joules

DEFIBRILLATION DURING THE PROCEDURE Stop the oxygen to avoid the hazard of fire Be sure that no one is touching the bed or the client when delivering the countershock

DEFIBRILLATION USE OF PADDLE ELECTRODES Apply conductive pads One paddle is placed at the third intercostal space to the right of the sternum; the other is placed at the fifth intercostal space on the left midaxillary line Apply firm pressure with the paddles Be sure that no one is touching the bed or the client when delivering the countershock

ANATOMICAL POSITION OF THE HEART From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

PADDLE PLACEMENT From Lewis SM, Heitkemper M, Dirksen S: Medical-Surgical Nursing: Assessment and Management of Clinical Problems (5th ed), St. Louis, 2000, Mosby.

AUTOMATIC EXTERNAL DEFIBRILLATOR (AED) Used by laypersons and emergency medical technicians for prehospital cardiac arrest Place the client on a firm dry surface Stop CPR Ensure that no one is touching the client to avoid motion artifact during rhythm analysis Place the electrode paddles in the correct position on the client’s chest Press the analyzer button to identify the rhythm, which may take 30 seconds; the machine will advise whether a shock is necessary

AUTOMATIC EXTERNAL DEFIBRILLATOR (AED) Shocks are recommended for pulseless VF only If shock is recommended, the shock is initially delivered at an energy of 200 joules If unsuccessful, the shock is repeated at 200 to 300 joules The third and subsequent shock will be at 360 joules If unsuccessful, CPR is continued for 1 minute, and then another series of 3 shocks are delivered each at 360 joules of energy

IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) DESCRIPTION Monitors cardiac rhythm and detects and terminates episodes of VT and VF It senses VT or VF and delivers 25 to 30 joules up to four times if necessary Used in clients with episodes of spontaneous sustained VT or VF unrelated to a myocardial infarction or in clients whose medication therapy has been unsuccessful in controlling life-threatening dysrhythmias Electrodes are placed in the right atrium and ventricle and apical pericardium; the generator is implanted in the abdomen

IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) From Lewis SM, Heitkemper M, Dirksen S: Medical-Surgical Nursing: Assessment and Management of Clinical Problems (5th ed), St. Louis, 2000, Mosby.

IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) CLIENT EDUCATION Basic functioning of the ICD How to perform cough CPR How to take the pulse; the pulse is taken daily and a diary of pulse rates is maintained Wear loose-fitting clothing Avoid contact sports and strenuous activities

IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) CLIENT EDUCATION Report any fever, redness, swelling, or drainage from the insertion site Report symptoms of fainting, nausea, weakness, blackouts, and rapid pulse rates to the physician During shock discharge, the client may feel faint or short of breath To sit or lie down if they feel a shock and to notify the physician

IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) CLIENT EDUCATION How to access emergency medical system Encourage the family to learn CPR Maintain a diary of any shocks that are delivered including the date, preceding activity, the number of shocks, and if the shocks were successful

IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (ICD) CLIENT EDUCATION Avoid electromagnetic fields directly over the ICD because they can inactivate the device Move away from the magnetic field immediately if beeping tones are heard, and notify the physician Keep a pacemaker ID in the wallet and obtain and wear a Medic Alert bracelet Inform all health care providers that an ICD is inserted

PACEMAKERS DESCRIPTION A temporary or permanent device that provides electrical stimulation and maintains the heart rate when the client’s intrinsic pacemaker fails to provide a perfusing rhythm

PACEMAKERS SETTINGS Synchronous or demand pacemaker: Senses the client’s rhythm and paces only if the client’s intrinsic rate falls below the set pacemaker rate Asynchronous or fixed rate: Paces at a preset rate regardless of the client’s intrinsic rhythm Overdrive pacing: To suppress the underlying rhythm in tachydysrhythmias so that the sinus node will regain control of the heart

PACEMAKERS SPIKES When a pacing stimulus is delivered to the heart, a spike (straight vertical line) is seen on the monitor or ECG strip The spike should be followed by a P wave indicating atrial depolarization, or a QRS complex indicating ventricular depolarization; this pattern is referred to as “capture,” indicating that the pacemaker successfully depolarized, or captured, the chamber

PACEMAKERS SPIKES If the electrode is in the ventricle, the spike is in front of the QRS complex; if the electrode is in the atrium, the spike is before the P wave If the electrode is in both the atrium and ventricle, the spike is before both the P wave and QRS complex

PACEMAKER SPIKES From Monahan, F. & Neighbors, M. (1998). Medical-surgical nursing: Foundations for clinical practice, ed 2, Philadelphia: W.B. Saunders

TEMPORARY PACEMAKERS NONINVASIVE TEMPORARY PACING (NTP) Used as an emergency measure or when a client is being transported and the risk of bradydysrhythmia exists A large electrode patch is placed on the chest and back

TEMPORARY PACEMAKERS NONINVASIVE TEMPORARY PACING (NTP) Wash the skin with soap and water prior to applying electrodes Do not shave the hair or apply alcohol or tinctures to the skin Place the posterior electrode between the spine and left scapula behind the heart, avoiding placement over bone Place the anterior electrode between V2 and V5 position over the heart

TEMPORARY PACEMAKERS NONINVASIVE TEMPORARY PACING (NTP) Do not place the anterior electrode over female breast tissue; rather, displace breast tissue and place under the breast Do not take the pulse or BP on the left side because the results will not be accurate due to the muscle twitching and electrical current Assure that electrodes are in good contact with the skin If loss of “capture” occurs, assess the skin contact of the electrodes and increase the current until “capture” is regained

TEMPORARY PACEMAKERS TRANSVENOUS INVASIVE TEMPORARY PACING Pacing lead wire is placed through antecubital, femoral, jugular, or subclavian vein into the right atrium for atrial pacing, or through the right ventricle, and positioned in contact with the endocardium Monitor cardiac rhythm continuously Monitor vital signs Monitor pacemaker insertion site Restrict client movement to prevent lead wire displacement

TRANSVENOUS INVASIVE TEMPORARY PACING From Thelan LA et al (1998) Critical care nursing (3rd ed). St. Louis: Mosby.

TEMPORARY PACEMAKERS EPICARDIAL INVASIVE TEMPORARY PACING Applied using a transthoracic approach The lead wires are loosely threaded on the epicardial surface of the heart after cardiac surgery

EPICARDIAL INVASIVE TEMPORARY PACING From Black, J. Hawks, J., and Keene, A. (2001). Medical-surgical nursing, ed 6, Philadelphia: W.B. Saunders

TEMPORARY PACEMAKERS REDUCING THE RISK OF MICROSHOCK Use only inspected and approved equipment Insulate the exposed portion of wires with plastic or rubber material (fingers of rubber gloves) when wires are not attached to the pulse generator, and cover with nonconductive tape Ground all electrical equipment using a three-pronged plug Wear gloves when handling exposed wires Keep dressings dry

PERMANENT PACEMAKERS Pulse generator is internal and surgically implanted in a subcutaneous pocket under the clavicle or abdominal wall The leads are passed transvenously via the cephalic or subclavian vein to the endocardium on the right side of the heart May be single-chambered, in which the lead wire is placed in the chamber to be paced, or dual-chambered, with lead wires placed in the atrium and right ventricle

PERMANENT PACEMAKERS It is programmed when inserted and can be reprogrammed if necessary by noninvasive transmission from an external programmer to the implanted generator Pacemakers are powered by either a lithium battery that has an average life span of 10 years, nuclear-powered with a life span of 20 years or longer, or are designed to be recharged externally

PACEMAKERS: CLIENT EDUCATION About the pacemaker including the programmed rate The signs of battery failure and when to notify the physician Report any fever, redness, swelling, or drainage from the insertion site Report signs of dizziness, weakness or fatigue, swelling of the ankles or legs, chest pain, or shortness of breath

PACEMAKERS: CLIENT EDUCATION Keep a pacemaker identification card in the wallet and obtain and wear a Medic Alert bracelet How to take the pulse, to take the pulse daily, and maintain a diary of pulse rates Wear loose-fitting clothing Avoid contact sports Inform all health care providers that a pacemaker is inserted Inform airport security about the pacemaker because the pacemaker may set off the security detector

PACEMAKERS: CLIENT EDUCATION Most electrical appliances can be used without any interference with the functioning of the pacemaker; however, advise the client not to operate electrical appliances directly over the pacemaker site Avoid transmitter towers and antitheft devices in stores If any unusual feelings occur when near any electrical devices to move 5 to 10 feet away and to check the pulse The importance of follow-up with the physician