Page 364 - fbkCardioDiabetes_2017

Evaluvation of Cardiac Syncope And ECG Markers of
340
Sudden Cardiac Arrest.

ly in standing positions or after change of posture
suggest vasovagal etiology. Similarly situations like
micturition cough/exercise triggering syncope sug-
gest vasovagal etiology. Palpitations preceding syn-
cope or syncope post exercise termination suggest
an arrhythmic cause. Syncope in lying down position
mostly suggests arrhythmic/cardiac cause.
High risk features in history are:

Syncope post exercise or in supine position.
Fig 1: Loss of R and deep Q waves.
Palpitations at time of syncope
2. Small voltage QRS complex indicate lack of elec-
Family history of sudden cardiac arrest (SCA) trically viable tissue and splintered QRS complexes
History of structural heart disease or coronary artery indicate a patchy scar. Small voltage ECG may be
disease (CAD) suggestive of disorders like restrictive cardiomyopa-
thy and amyloidosis.
Past history of angioplasty or bypass surgery.

Risk stratification on physical examination:
High risk features suggesting cardiac etiology on
physical examination are:
Heart rate less than 60 bpm or more than 150 bpm
suggesting arrhythmic cause.

Irregular heart rate suggest atrial fibrillation with vary-
ing R-R interval.
Low blood pressure may suggest tachycardia with Fig 2: Splintered QRS with low voltage.
fast rates.
3. Severe LV hypertrophy is suggestive of hypertro-
Postural drop of BP suggests orthostatic intolerance. phic heart disease.
Chest examination may suggest cardiomegaly.
Ejection systolic murmur is suggestive of aortic ste-
nosis/ HOCM.
S3 on examination may suggest severe LV dysfunc-
tion.

Risk stratification by ECG:
Though patients of syncope may have normal ECGs,
it is important to look for subtle changes which may
suggest arrhythmic problem or structural heart dis-
ease. ECG changes would give a clue to cardiac eti-
ology of syncope (2).
Fig 3: LVH by voltage criteria: S wave in V2 + R wave
A. ECG markers which may suggest in V5 > 35 mm
structural heart disease: 4. Increased duration of QRS complex is a marker

1. Loss of R waves and presence of Q wave or QS for delayed intra ventricular conduction and if more
pattern suggest a transmural scar, evolved infarct than 150 ms is an independent predictor of VT/VF.
which are substrate for arrhythmias.
5. ST segment and T wave changes: Persistent ST
elevation indicates aneurysm of LV or ongoing isch-
emia. ST depression and/or bifid or deeply inverted
T waves suggests ischemia of myocardium. Spade

GCDC 2017