General responses to selected questions from Joel Braunstein, MD, of Johns Hopkins University and Joseph Toscano, MD.
I have been diagnosed with SVT and take Atenolol daily. Will there come a time when Atenolol no longer controls the symptoms and the dosage will need to be increased? I am experiencing times when the rapid beat seems like it will start, but doesn't. This is followed by a slight dizziness
Supraventricular tachycardia (SVT) is a general term that describes a host of abnormally fast heart rhythms that arise from above the ventricles, or lower pumping chambers, of the heart. These rhythms can be extremely fast (heart rates ranging between 150-250 beats per minute), tend to be intermittent, and - if left untreated over long periods of time - can lead to heart failure.
Fortunately, SVT is usually a benign condition in the absence of structural heart disease (such as valvular heart disease, prior heart attack, or severely weakened heart). SVT can cause disturbing symptoms that impact an individual's quality of life, however, including palpitations, shortness of breath, chest pain, light-headedness, and even passing out. The symptoms you describe suggest that you may still be experiencing very brief episodes of the SVT, despite being on medication.
The medication you describe, Atenolol, is a commonly used medication for the long-term control of SVT. There are more powerful medications to suppress the onset of SVT - however, these medications (known as anti-arrhythmics) usually carry additional side effects to those observed with Atenolol alone. SVT does not necessarily need to follow a progressive course. However, SVT in elderly individuals may be a signal of other conduction system heart disease that can progress over time. This condition is known as tachycardia-bradycardia syndrome (or sick sinus syndrome). The progression of this condition could make it such that periods of SVT become more protracted and more difficult to control with medications like Atenolol because of added risk of the side effects.
The treatment of SVT in cases that do not respond to typical medications is typically a radiofrequency catheter ablation of the portion of the heart that is responsible for the origin of the SVT. Performed by cardiologists who are specially trained to manage these heart rhythms, this ablation technique is performed in a catheterization laboratory, usually only takes a few hours to complete, and usually allows patients to return home from the hospital in the same day. This procedure cures SVT in the majority of cases. Older individuals who have SVT as part of their tachycardia-bradycardia syndrome may also or alternatively undergo placement of a pacemaker.