ECG: Digitalis Effect

PROF. DR.RAMASAMY’S UNITG.BALAJI MD PG

45 YEAR FEMALE PRESENTED WITH C/OPALPITATION FOR 1 MONTHEXERTIONAL BREATHLESSNESS FOR 2

MONTHS.ON AUSCULTATION THE PATIENT HAD A

DIASTOLIC MURMUR

SINUS RHYTHMRATE 120/MINREGULAR RHYTHMP WAVE DURATION- 0.12 SECONDSFRONTAL PLANE P WAVE AXIS-AROUND 45

DEGREE QT INTERVAL- 320 MILLISECONDSQTC INTERVAL- 420 MILLISECONDS QRS - RIGHT AXIS DEVIATION. 140

DEGREES

LEFT ATRIAL ENLARGEMENTWIDE NOTCHED P WAVE IN I, V4 TO V6DURATION OF P WAVE IN LEAD I IS 0.12 SEC,

NOTCH 0.04 SECONDSDELAY IN INSCRIPTION OF TERMINAL

DEFLECTION OF P WAVE INLEAD VI IS 0.08 SECONDS

RIGHT ATRIAL ENLARGEMENTTALL INITIAL COMPONENT OF P WAVE IN

LEADS II, III, Avf.AMPLITUDE OF P IN LEAD II IS 3 MM [NORMAL

2MM]P TRICUSPIDALE INITIAL COMPONENT OF P WAVE TALLER

THAN TERMINAL COMPONENT

RIGHT VENTRICLE ENLARGEMENT TALL R WAVE IN LEAD VI RIGHT AXIS DEVIATION. AROUND 140

DEGREE T INVERSION IN LFEAD V1 TO V3

INDICATING A POSTERIOR DEVIATION OF T WAVE

rs COMPLEX IN V4 TO V6. CLOCKWISE ELECTRICAL ROTATION

EVIDENCE OF PULMONARY HYPERTENSION

RIGHT ATRIAL ENLARGEMENTRIGHT AXIS DEVIATIONCLOCKWISE ELECTRICAL ROTATION

DIGITALIS EFFECTSHORTENED QTC INTERVALMIRROR IMAGE OF CHECK OR CORRECTION

MARK IN LEADS V1 TO V3NO DEPRESSION OF PROXIMAL PART OF ST

SEGMENT

MITRAL STENOSIS WITH LEFT ATRIAL ENLARGEMENT , RIGHT ATRIAL ENLARGEMENT AND PULMONARY HYPERTENSION WITH DIGITALIS EFFECT

ST SEGMENT STRAIGHT DOWNWARD SLOPE WITH TERMINAL

RISE IS MIRROR IMAGE OF CHECK OR CORRECTION MARK IN LEADS WITH DOMINANTLY UPRIGHT QRS COMPLEX

T WAVE THERAPEUTIC DOSES DIMNISH MAGNITUDE BUT

NOT DIRECTION OF T WAVE. TOXIC DOSES CHANGE DIRECTION OF T WAVE OR

T WAVE DONOT RISE ABOVE THE BASELINE.

SHORTENING OF QTC INTERVALDIGITALIS ACCELARATE ACTIVITY OF

VENTRICULAR SUB ENDOCARDIUM AND SHORTENS THE RECOVERY PERIOD.

QTC IS SHORTENED. IT OCCURS EARLY DURING COURESE OF DIGITALIS ADMINISTRATION.

SHORTENS THE REFRACTORY PERIOD OF ATRIAL MYOCARDIUM

LENGTHENS THE REFRACTORY PERIOD OF SA AND AV NODE

ABNORMAL CARDIAC RHYTHMCAUSES ALL ARRYTHMIAS EXCEPT TYPE II 2ND

DEGREE AV BLOCK.VENTRICULAR EXTRASYSTOLES , BIGEMINI, VENTRICULAR TACHYCARDIAS, AV BLOCKS.

DIGITALIS HAS NO EFFEFT ON QRS COMPLEXES

MAY AT TIMES CAUSE PROMINENCE OF U WAVE