Which ECG changes are associated with hypocalcemia?

The ECG hallmark of hypocalcaemia is QT interval prolongation secondary to a prolonged ST segment. This is a result of increase in the duration of phase two of the action potential of cardiac muscle. QTc interval prolongation is directly proportional to the degree of hypocalcaemia [3].

What ECG changes are seen in hypocalcemia and hypercalcemia?

On electrocardiography (ECG), characteristic changes in patients with hypercalcemia include shortening of the QT interval. ECG changes in patients with very high serum calcium levels include the following [19, 20, 21] : Slight prolongation of the PR and QRS intervals. T wave flattening or inversion.

Why does hypocalcemia increase QT interval?

Hypocalcaemia is a recognised cause of QT prolongation via prolongation of the plateau phase of the cardiac action potential. This causes calcium ion channels to remain open for a longer period, allowing a late calcium inflow and the formation of early after-depolarisations.

What does hypercalcemia cause on ECG?

(Ref. 2,3) Hypercalcemia has also been known to cause an ECG finding mimicking hypothermia, known as an Osborn wave. (Ref. 4) Hypocalcemia: The most significant sign is intermittent QT prolongation, or intermittent prolongation of the QTc (corrected QT interval) secondary to a lengthened ST segment.

What arrhythmia is caused by hypocalcemia?

Hypocalcemia can result in both ST segment modification and QT interval prolongation and, when severe, can predispose to life-threatening ventricular arrhythmias (3). Acute hypocalcemia can result in severe symptoms that require rapid admission to hospital and prompt correction.

What are Q waves indicative of?

Technically, a Q wave indicates that the net direction of early ventricular depolarization (QRS) electrical forces projects toward the negative pole of the lead axis in question. Although prominent Q waves are a characteristic finding in myocardial infarction, they can also be seen in a number of noninfarct settings.

Does hypokalemia cause prolonged QT interval?

Hypokalemia is another common risk factor in drug-induced LQTS. Low extracellular potassium paradoxically reduces IKr by enhanced inactivation [42] or exaggerated competitive block by sodium [43]. As a result, hypokalemia prolongs the QT interval.

What is Wellens syndrome?

Wellens syndrome describes a pattern of electrocardiographic (ECG) changes, particularly deeply inverted or biphasic T waves in leads V2-V3, that is highly specific for critical, proximal stenosis of the left anterior descending (LAD) coronary artery. It is alternatively known as anterior, descending, T-wave syndrome.