Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Appendix B Pathophysiology and Clinical Implications of Arrhythmias

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Cardiac Output  Total volume of blood pumped by heart in one minute Heart Rate x Stroke Volume = Cardiac Output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ How Arrhythmias Impact Cardiac Output  Heart Rate:  Bradycardias  Tachycardias  Stroke Volume:  Ventricular rhythms

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Symptoms of Decreased Cardiac Output  Anxiety  Chest pain  Shortness of breath  Diaphoresis  Hypotension  Cool, clammy skin  Cyanosis  Decreased consciousness

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Treatment Principles MechanismTreatment Principle BradycardiaRate is too slow Speed up rate TachycardiaRate is too fast Slow down rate Ventricular Irritability Contraction is erratic Suppress irritable focus

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Normal Sinus Rhythm Significance  Normal cardiac pattern Clinical Picture  Does not produce symptoms

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Sinus Bradycardia Significance  Can precede blocks or asystole  Can precipitate escape rhythms or ventricular irritability  Can be caused by AMI, vagal stimulation, increased intracranial pressure  Can reflect normal, athletic heart Clinical Picture  Slow, regular pulse  Can cause signs/symptoms of decreased cardiac output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Sinus Tachycardia Significance  Usually a compensatory response to fever, activity, pain, anxiety, hypovolemia, heart failure, etc.  Dangerous in AMI (can extend infarct) Clinical Picture  Rapid, regular pulse  Probably asymptomatic  Possibly palpitations, dyspnea

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Sinus Arrhythmia Significance  Common in children and young adults Clinical Picture  Irregular pulse  Rarely causes symptoms

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Premature Atrial Contractions Significance  Usually benign  Can be early sign of CHF  Can lead to atrial tachyarrhythmias  Causes include fatigue, hypoxia, dig-toxicity, caffeine, ischemia, CHF, alcohol Clinical Picture  Rarely causes symptoms

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Wandering Pacemaker Significance  Normal; often seen in very old or very young, or in athletes  Persistence of junctional rhythm can indicate heart disease Clinical Picture  Rarely causes symptoms

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Atrial Tachycardia Significance  Very dangerous in AMI or heart disease  Commonly caused by dig-toxicity Clinical Picture  Rapid, regular pulse  May show signs/symptoms of drop in cardiac output  Can cause pulmonary edema, CHF, shock

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Atrial Flutter Significance  Rapid ventricular rate and loss of atrial kick can drop cardiac output  Risk of pulmonary and cerebral emboli  Can cause CHF or myocardial ischemia  Seen in CAD, rheumatic heart disease Clinical Picture  Pulse can be regular or irregular, fast or slow  Rapid ventricular rate can cause signs/symptoms of low cardiac output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Atrial Fibrillation Significance  Very rapid rate can lead to CHF or myocardial ischemia  Threat of pulmonary or cerebral emboli  Commonly caused by dig-toxicity Clinical Picture  Irregular pulse, can be fast or slow  Can have pulse deficit  Can cause signs/symptoms of low cardiac output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Premature Junctional Contractions Significance  May precede AV block Clinical Picture  Rarely causes signs/symptoms

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Junctional Escape Rhythm Significance  Fail-safe mechanism  Can be normal, as with athletes Clinical Picture  Slow pulse  If rate is slow enough, can cause signs/symptoms of low cardiac output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Accelerated Junctional Rhythm Significance  Indicates irritable junction overriding normal pacemaker  Often caused by AMI, open-heart surgery, myocarditis, dig- toxicity Clinical Picture  Usually asymptomatic

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Junctional Tachycardia Significance  Indicates irritable junction overriding normal pacemaker  Often caused by AMI, open-heart surgery, myocarditis, dig- toxicity Clinical Picture  Rapid, regular pulse  Can cause signs/symptoms of low cardiac output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ First Degree Heart Block Significance  Can be caused by anoxia, ischemia, AV node malfunction, edema following open-heart surgery, dig-toxicity  Can lead to more serious AV block Clinical Picture  Usually asymptomatic

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Second Degree Heart Block, Type I (Wenckebach) Significance  Common following inferior MI  Can progress to more serious AV block Clinical Picture  Irregular pulse  Usually asymptomatic

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Second Degree Heart Block, Type II Significance  Can be caused by anoxia, edema after open-heart surgery, dig-toxicity, hyperkalemia, anterior MI Clinical Picture  Slow rate can cause signs/symptoms of low cardiac output

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Third Degree Heart Block Significance  Can progress to ventricular standstill Clinical Picture  Very slow rate and abnormal pacemaker site severely impair cardiac output  Patients will frequently be unconscious from poor perfusion  Cardiac failure can follow quickly

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Premature Ventricular Contractions Significance  Indicate ventricular irritability; increasing frequency indicates increasing irritability  Causes include ischemia/infarction, hypoxia, acidosis, hypovolemia, electrolyte imbalance, caffeine, smoking, alcohol Clinical Picture  Patients can feel PVCs and be distressed by them  Pulse is irregular  Perfusion usually not impaired unless PVCs become frequent  Many factors can cause chronic PVCs in adults PVCs considered dangerous if: –more than 6 per minute –patterns (bigeminy, trigeminy, etc.) –couplets –runs –R-on-T phenomenon –multifocal

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Ventricular Tachycardia Significance  Can quickly progress to ventricular fibrillation Clinical Picture  Patient will begin to lose consciousness as perfusion drops

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Ventricular Fibrillation Significance  Lethal arrhythmia  Indicative of extreme myocardial irritability Clinical Picture  Patient is clinically dead

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Idioventricular Rhythm Significance  Carries poor prognosis  Often associated with large MI and damage to large amount of ventricular muscle mass Clinical Picture  Patient is clinically dead

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Asystole Significance  Carries very poor prognosis  Often seen after patient has been in arrest for some time Clinical Picture  Patient is clinically dead

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Matrix of Clinical Impact RATE PACEMAKER FastSlow Supraventricular Ventricular

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Matrix of Clinical Impact RATE PACEMAKER Slow Supraventricular Ventricular Junctional Escape Rhythm Third Degree Heart Block Fast Normal Sinus Rhythm Sinus Bradycardia Sinus Arrhythmia Sinus Tachycardia Wandering Pacemaker Atrial Flutter Atrial Fibrillation PACs PJCs Atrial Tachycardia Accelerated Junctional Rhythm First Degree Heart Block Wenckebach Second Degree Heart Block Type II Junctional Tachycardia Supraventricular Tachycardia Normal Idioventricular Rhythm Asystole PVCs Ventricular Tachycardia Ventricular Fibrillation

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Matrix of Clinical Impact RATE PACEMAKER FastSlow Supraventricular Ventricular BRADYCARDIAS VENTRICULAR IRRITABILITY TACHYCARDIAS

Gail Walraven, Basic Arrhythmias, Sixth Edition ©2006 by Pearson Education, Inc., Upper Saddle River, NJ Matrix of Clinical Impact RATE PACEMAKER FastSlow Supraventricular Ventricular BRADYCARDIAS VENTRICULAR IRRITABILITY TACHYCARDIAS INCREASE RATE DECREASE RATE SUPPRESS IRRITABILITY