RHYTHM ANALYSIS DAN MUSE, MD

EKG EKG’S are loaded with acronyms. EKG….LBBB….QTc……IRBBB……ETC

EKG The one you should remember is……..KISS

EKG KEEP IT SIMPLE STUPID!

EKG EKG’s record electrical patterns that allow for medical interpretations Acute Myocardial Infarction Conduction Abnormalities Rhythm Disturbances Metabolic Abnormalities Drug Toxicity Pericarditis Etc……

EKG GRID The paper is graph paper that measures speed horizontally and amplitude vertically. The horizontal box equals 0.04 seconds. The darker box representing 5 small boxes equals 0.2 seconds

EKG GRID The vertical box measures amplitude. The amplitude is a measure of voltage given in millivolts or MV 10 small boxes or 2 large boxes is equal to 1 mv

EKG GRID EKG GRID

P WAVE P wave represents the depolarization of the atrium Sinus node is in the right atrium resulting in the right atrium depolarizing first and then the left atrium Normal duration is 0.12 sec…3 small boxes.

P WAVE P WAVE

PR INTERVAL PR interval is measured from the beginning of the p wave and to the beginning of the r (or q) wave. It measures the time of atrial depolarization (p wave) conduction through the av node and conduction through the his-purkinje. Normal duration is .14 to .20 seconds.

PR INTERVAL PR INTERVAL

QRS COMPLEX Q wave: a negative deflection indicating septal depolarization Small Q waves may be seen in limb leads and v4-6 R wave: a positive deflection reflecting the depolarization of the left ventricle S wave: the negative deflection reflects the depolarization of the high lateral wall

ST SEGMENT Begins after the heart has depolarized and ends when the repolarization begins. Ekg is “silent” during this time and should be isoelectric or at the baseline.

T WAVE Represents ventricular repolarization. Slower than depolarization and the wave has a slow broad upstroke, returning quickly to baseline. Depolarization travel endo to epicardium (inside-outside) with repolarization traveling epi to endocardium (outside-inside)

EKG COMPLEXES COMPLEXES

QT INTERVAL Is a measure of the heart’s repolarization. Measured from the QRS through the T wave Changes with rate. A faster heart rate has a shorter QT interval and a slower heart rate has a longer one.

QT INTERVAL QT Interval is corrected to account for the heart rate. QTc   =   QT interval  ÷  square root of the RR interval (in sec ) Normal QTc is less then or equal to 0.44 sec.

QT INTERVAL QT INTERVAL

U WAVE Occurs after the T wave Mechanism is not exactly understood Has a low amplitude, usually less than .2 mv (2 small boxes) Seen in metabolic abnormalities such as hypokalemia

U WAVE U WAVE

EKG WAVES THE WHOLE ENCHILADA

HEART RATE Heart rate is measured by determining the distance between the QRS complexes. Exact rate is not necessary…range will suffice.

HEART RATE The rate is most easily determined by dividing 60 seconds by the number of large blocks separating the QRS complexes. 60 SECONDS / 0.2 (ONE LG BLOCK) = 300 60 SECONDS / 0.4 (2 LG BLOCKS) = 150 60 SECONDS / 0.6 (3 LG BLOCKS) = 100

HEART RATE NORMAL HEART RATE: 60-100 BRADYCARDIA: Less then 60 TACHYCARDIA: Greater then 100

RHYTHM ANALYSIS Locate the P wave Is every P wave the same? Is the P wave associated with a QRS complex? Is the p wave hidden in the QRS. Seen in Junctional or AV nodal reentrant tachycardia. Is the P wave hidden in the ST segment…AV reentrant or ventricular tachycardia.

RHYTHM ANALYSIS What is the p wave rate (P-P Interval)? Less than 60….Bradycardia 100-180….Sinus Tachycardia 140-220….Atrial Tachycardia, AV Nodal Reentrant Tachycardia, AV Reentrant Tachycardia. 260-320…..Atrial Flutter

RHYTHM ANALYSIS OF RAPID RATE What is the morphology of the qrs? Less than 0.12 sec: (Narrow Complex) Supraventricular Greater than 0.12 sec: (Wide Complex) Supraventricular With Aberrant Conduction Or Ventricular

RHYTHM ANALYSIS Match the findings to the patient. Different age groups, different diseases and different lifestyles may produce different findings on the EKG.

SINUS BRADYCARDIA Normal complexes Rate less than 60

SINUS BRADYCARDIA

SINUS TACHYCARDIA Rate a sinus rhythm 100-180 Normal complexes

SINUS TACHYCARDIA

IRREGULARLY IRREGULAR ATRIAL FIBRILLATION Typically rapid but chronically can be a slower controlled rate. Don’t see P waves because so many are firing off at the same time. IRREGULARLY IRREGULAR

ATRIAL FIBRILLATION

ATRIAL FLUTTER Rate is variable and based on the recurrent conduction of the P waves P waves can have a saw tooth pattern Rate of 150…..Think A-Flutter P waves have a propensity to hide in the T wave on a 2:1 conduction (for every QRS complex there are 2 P waves; 2:1 conduction)

ATRIAL FLUTTER

PVC’S PREMATURE VENTRICULAR CONTRACTIONS Wide complex QRS intermixed with narrow complex QRS. Always associated with a compensatory pause which when added with the previous normal QRS equals two QRS complexes. May come in bunches.

1ST DEGREE AV BLOCK Prolonged PR interval No medical consequence

1ST DEGREE AV BLOCK

3RD DEGREE AV BLOCK Complete blockage at the AV node Results in p waves and the QRS complexes beating separately

3RD DEGREE AV BLOCK 3RD DEGREE BLOCK

VENTRICULAR TACHYCARDIA A wide complex ventricular tachycardia. Rhythm is regular.

VENTRICULAR TACHYCARDIA

TORSADES A ventricular arrhythmia that rotates on its axis. TORSADES = twists in French. Treated with magnesium.

TORSADES TORSADES

VENTRICULAR FIBRILLATION Irregular ventricular complexes. The smaller the complexes the less likely you can reverse the process. NEXT COMPLEX…..ASYSTOLE!

VENTRICULAR FIBRILLATION