Long & Short QT Syndrome causes, Symptoms, & Treatment in India

What are Long and Short QT syndromes?

The electrical system of your heart controls your pulses by using two factors. One is your heart rate or the number of times your heart beats per minute. The second factor is the rhythm of your heart or the synchronization between the two atria and the two ventricles of your heart. To achieve these, it is the duty of the electrical system to maintain a steady heart rate and rhythm in the sinus. The sinus controls the contraction of atria and ventricles. Q and T waves refer to the electrical impulses that are the cause of contraction and expansion of the chambers of the heart. ‘QT interval’ is the time lapse between the start of the Q wave and the end of the T wave, in the electrical cycle of the heart.

On an average, the QT interval lasts from 0.2 to 0.4 seconds. If the QT interval is longer, it could cause imbalances in the rhythm of the heart, called arrhythmia. This phenomenon is called ‘Long QT syndrome’. If the QT interval is shorter, it might indicate that the blood has high levels of calcium content. This is referred to as ‘Short QT syndrome’.

Symptoms

Usually, many people with long QT syndrome display no symptoms. Some may have the following symptoms:

Syncope
Seizures
Sudden cardiac death

In short QT syndrome, patients might experience the following symptoms:

Palpitations
Syncope
Abnormal rhythms of the heart
Sudden cardiac death, due to ventricular fibrillation

Causes

Both long and short QT syndromes are congenital and are associated with genetic mutations. Although other causes are not completely understood, the risk factors of Long QT syndrome include:

Belonging to female gender
Liver or renal impairment
Progressing age
Family history of the syndrome
Other cardiovascular diseases
Electrolytic imbalance – Hypomagnesemia, Hypocalcemia, Hypokalemia
Concurrent administration of interacting drugs

As far as short QT syndrome is considered, researchers suggest that the QT duration decreases owing to increased activity of outward potassium currents in phases of the heart.

Risks

Although other causes are not completely understood, the risk factors of Long QT syndrome include:

Belonging to female gender
Liver or renal impairment
Progressing age
Family history of the syndrome
Other cardiovascular diseases
Electrolytic imbalance – Hypomagnesemia, Hypocalcemia, Hypokalemia

Prevention

Nothing much can be done to prevent long and short QT syndrome because the disease is caused due to genetic mutations.

How is it diagnosed?

Short QT syndrome is extremely rare and must be diagnosed by a well-trained electrophysiologist, who is well versed with QT syndromes. The specialist would use electrocardiography, echocardiography...

Thyroid tests
Electrocardiography for all family members
Genetic testing for all family members
Checking of Potassium and Magnesium levels in the serum

How is it treated?

Those with long QT syndrome are advised to refrain from participating in competitive sports, strenuous exercise, and being subjected to stress-related emotions. They should also avoid the following, Anesthesia, Asthma drugs, Antihistamines, Antibi..

Pharmacotherapy
Use of Beta blockers like Propranolol, Nadolol, Metoprolol or Atenolol.
Device therapy
Implantation of cardioverter defibrillator, pacemaker.
Left cervicothoracic stellectomy
Surgically removing the stellate ganglion.