Supraventricular tachycardia is seldom fatal and can often be terminated easily in a cardiac care set up. Sometimes it can be terminated even without medications by a cough, strain or a gag reflex or a splash of ice cold water over the face as well. Another method which emergency personal use to terminate the episode is by giving a pressure over the carotid sinus in the neck. But this should not be attempted by a lay person as it has its own risks. Carotid sinus massage should be done carefully, with ECG monitoring in an emergency care set up. If the disorder is left untreated for a long period,it can cause weakening of the heart muscle causing a fall in blood pressure and heart failure. Recurrence can be prevented by medications taken on a long term basis. Some with very infrequent episodes also opt for a “pill in the pocket” approach by taking a tablet as soon as the symptom occurs. Definitive treatment these days is in the form of identification of the site by cardiac electrophysiology studies and radio frequency catheter ablation. In this procedure, small multi electrode catheters are introduced into the heart, monitoring the electrical signal from each location. One the exact site of the abnormality is localized, a radiofrequency signal is delivered to cause a tiny controlled superficial burn which stops the abnormal electrical activity within the heart. This procedure has a fairly high success rate and few complications and hence is being resorted to by most persons to avoid the problems of taking long term medications.

Atrial fibrillation is an electrical disorder of the upper chambers of the heart in which regular electrical pulses from the sinus node are replaced by fast disorganized electrical activity which causes the upper chambers (atrial) to stand still and quiver. This can lead to blood clot formation in these chambers which can move along the blood vessels to regions like the brain and cause disorders like stroke or paralysis.

There could be multiple roles for a pacemaker in patients with atrial fibrillation. In those with recurrent rather than persistent atrial fibrillation, pacing the atrium (upper chamber of the heart) simultaneously from multiple sites can reduce the recurrence of atrial fibrillation. Another role is to have a pacemaker when atrial fibrillation is refractory. In drug refractory atrial fibrillation, radiofrequency current is used to cut off the pathways which conduct the atrial pulses to ventricles using specially designed electrode catheters. This produces a complete heart block and requires a pacemaker to give regular electrical pulses for the ventricles to contract regularly.

Interestingly, short QT interval can also cause cardiac arrhythmias. There is a condition called congenital short QT syndrome, which is more likely to cause atrial arrhythmias. Individuals with both long QT syndrome and short QT syndrome require implantation of an ICD (implantable cardioverter defibrillator) if they have significant cardiac arrhythmia, which can lead to cardiac arrest.