Search results
Results from the WOW.Com Content Network
Pseudo-ST-depression, which is a wandering baseline due to poor skin contact of the electrode [3] Physiologic J-junctional depression with sinus tachycardia [3] Hyperventilation [3] Horizontal ST depression in V4, V5, V6 leads during a cardiac stress ECG. Other, non-ischemic, causes include: Side effect of digoxin [4] [3] Hypokalemia [4] [3]
ECG would be abnormal in 75 to 95% of the patients. Characteristic ECG changes would be large QRS complex associated with giant T wave inversion [4] in lateral leads I, aVL, V5, and V6, together with ST segment depression in left ventricular thickening. For right ventricular thickening, T waves are inverted from V2 to V3 leads.
Diagnosis is based on an ECG showing ST-segment depression at the J-point of 1 to 3 mm in leads V1 to V6, with tall and symmetrical T waves. [1] The ST-segment is upsloping and there is also often ST-segment elevation of 0.5 to 2 mm in lead aVR. [1] [2] The QRS complex is either normal or slightly wide. [1]
The hexaxial reference system is a diagram that is used to determine the heart's electrical axis in the frontal plane.. In electrocardiography, left axis deviation (LAD) is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between −30° and −90°.
ST or QRS segment changes, [34] e.g. more than 2 mm [33] horizontal or downsloping [34] ST segment depression in non-Q wave leads, or marked axis shift; Arrhythmias other than sustained ventricular tachycardia e.g. Premature ventricular contractions, both multifocal or triplet; heart block; supraventricular tachycardia or bradyarrhythmias [34]
Schematic representation of normal ECG. In electrocardiography, the ST segment connects the QRS complex and the T wave and has a duration of 0.005 to 0.150 sec (5 to 150 ms). It starts at the J point (junction between the QRS complex and ST segment) and ends at the beginning of the T wave.
The presentation and symptoms a patient can present with are varied and often dependent on the underlying cause of the junctional rhythm. Patient's can be asymptomatic for example, or experience difficulty breathing and chest pain if they have underlying congestive heart failure.
[4] [6] Unstable angina is considered to be present in patients with ischemic symptoms suggestive of an acute coronary syndrome and no change in troponin levels, with or without changes indicative of ischemia (e.g., ST segment depression or transient elevation or new T wave inversion) on electrocardiograms. [4]