Supraventricular tachycardia (SVT) is a tachycardia involving the atrium and/or the atrioventricular node (AV node). SVT is caused by a reentry pathway in about 90% of patients and an irritable focus due to abnormal automaticity or triggered activity in the remaining 10% of patients.
Symptoms of SVT
Usually, patients with SVT see a physician first in their teens, twenties, thirties or forties, but SVT can begin at any age. Patients usually have “spells” consisting symptoms of palpitations or out right tachycardia. Associated symptoms may include chest pain, pulsations in the neck, dyspnea, light-headedness, fatigue, sweating, etc. After a spell of SVT, the patient may have urinary frequency (due to release of ANF from the atria) or may feel fatigued for hours to days.
Diagnosis of SVT
SVT can be documented by a regular ECG performed at the time that the patient’s heart is racing if the patient goes to the emergency room. Patients who have daily episodes of SVT can have a 24-hour holter monitor placed to document the SVT. More commonly, patients may have monthly episodes and can use an external event monitor to record episodes and call them in on a toll-free telephone number. More rare episodes are difficult to document unless the patient waits until an episode occurs and then seeks medical attention at an emergency room or physician’s office. Patients who call 911 may have their episode of SVT documented by the paramedics en route to the hospital. Patients who are in the hospital wearing a telemetry monitor may have their SVT documented. Internal looped monitors are not usually deployed just to document SVT. However when such monitors are inserted in patients with syncope, SVT is occasionally documented. The heart rate of SVT can be from just over 100 beats per minute to nearly 300 beats per minute. Usually, the heart rate is between 160 and 220 beats per minute.
Acute care of SVT at home
Patients frequently ask what to do when they have an episode of SVT. The most important factor is for them to use common sense. If they feel very bad (severe chest pain, severe dyspnea) then calling 911 is prudent. Lesser degrees of symptoms give the patient the opportunity to try vagal maneuvers to see if they can get their heart rhythm back to normal. The only maneuvers that are safe to try at home are the Valsalva maneuver or the Muller maneuver. Other maneuvers are not recommended. Eyeball pressure has resulted in retinal injuries. Immersing the face in ice water has rarely caused cardiac arrest. Gagging seldom works to restore normal rhythm. Patients that tolerate their SVT without significant symptoms may elect to wait at home or even try to fall asleep in hopes that the episode will resolve on its own. Most patients will eventually go to the emergency room after waiting at home for a while if SVT persists.
Care of SVT in the emergency room
Doctors after recording and ECG and assessing the patients vital signs will decide whether the patient is really in danger (hypotension, severe chest pain, dyspnea) or not. If the patient is unstable, the doctor will sedate the patient and perform external cardioversion. If the patient seems stable, the doctor may ask the patient to perform vagal maneuvers to see if sinus rhythm can be restored. If this is ineffective, then medications can be given intravenously such as adenocard, verapamil, diltiazem or beta blockers. If these are ineffective other medications such as ibutilide, procainamide or rarely even amiodarone can be tried. If nothing succeeds in restoring normal rhythm, then eventually external cardioversion is performed. Usually once sinus rhythm is restored, the patient can be discharged rather than admitted to the hospital.
Work-up of SVT
Patients with a history of SVT should be seen by a cardiologist or even better by an electrophysiologist. The typical workup of patients with SVT involves having an echocardiogram done to search for structural heart disease. Patients with prominent symptoms of angina, or risk factors for coronary artery disease, may needstress testing or even a coronary angiography. Patients who might be treated with antiarrhythmic drugs need blood tests done to assess renal and hepatic function.
Prognosis of SVT
Unless structural heart disease is present, the prognosis of patients with SVT is excellent. As mentioned above, SVT does not shorten life – it does not lead to death, stroke or myocardial infarction. Should an episode of SVT arise while the patient is sleeping, they will be awakened by the symptoms. However, SVT will recur at some point in nearly all patients who do not die of another cause. For patients who have just experienced their first episode of SVT, it is impossible to say when the next episode will occur. For this reason, many of such patients take a wait and see approach to their SVT. As years and decades pass, nearly every patient experiences more frequent and/or more long-lasting episodes. It is also common for the patients to feel worse physically with their SVT as they get older.
Treatment of SVT
Usually structural heart disease is not present in patients with SVT. Unless WPW is present, SVT is a nuisance and not life-threatening. Because of this, the treatment of SVT does not prolong life. The only other reason to treat SVT then is to prevent the patient from having symptoms from their tachycardia. There are rare patients who are in SVT at least 90% of the day with heart rates over 130 beats per minute. Such patients may develop a tachycardiomyopathy in which case treatment is mandatory.
Patients with SVT have four general options for therapy:
Doing nothing to prevent or cure SVT, taking medications having a percutaneous ablation for cure performed having open-heart surgery.
Practically, patients needing open-heart surgery for another reason may have a surgical approach to their SVT, but this is quite rare. For the remainder, it is living with SVT, taking heart rhythm medications, or having an ablation for cure.
So my daughter Courtney has SVT, and has been feeling some uncomfortable moments when her hearts rate is over 100 beats per minute. She has experienced SVT for several months now, and will have her procedure on January 19th. Although the out come of this procedure is at a 95% rate, I am soliciting your prayers. Courtney is only 26 years old, and even though she has purposely loss weight after having this last baby. We have found out that SVT is not about size. At 26, Courtney is currently taking a beta blocker called Metoprolol.
What is metoprolol?
Metoprolol is a beta-blocker that affects the heart and circulation (blood flow through arteries and veins).
Metoprolol is used to treat angina (chest pain) and hypertension (high blood pressure). It is also used to treat or prevent heart attack.
Metoprolol may also be used for other purposes not listed in this medication guide.
You should not use metoprolol if you have a serious heart problem (heart block, sick sinus syndrome, slow heart rate), severe circulation problems, severe heart failure, or a history of slow heart beats that caused fainting.
Before taking this medicine:
You should not use this medication if you are allergic to metoprolol, or other beta-blockers (atenolol, carvedilol, labetalol, nadolol, nebivolol, propranolol, sotalol, and others), or if you have:
a serious heart problem such as heart block, sick sinus syndrome, or slow heart rate; severe circulation problems; severe heart failure (that required you to be in the hospital); or history of slow heart beats that have caused you to faint.
To make sure metoprolol is safe for you, inform your doctor if you have the following: asthma, chronic obstructive pulmonary disease (COPD), sleep apnea, or other breathing disorder; diabetes (taking metoprolol may make it harder for you to tell when you have low blood sugar); liver disease; congestive heart failure; problems with circulation (such as Raynaud’s syndrome); a thyroid disorder; or pheochromocytoma (tumor of the adrenal gland).
FDA pregnancy: It is not known whether metoprolol will harm an unborn baby. Tell your doctor right away if you become pregnant while using this medication.
Pregnancy and breastfeeding warnings
Metoprolol can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
Metoprolol is not approved for use by anyone younger than 18 years old.
How should I take metoprolol?
Take metoprolol exactly as prescribed by your doctor. Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Take the medicine at the same time each day.
Metoprolol should be taken with a meal or just after a meal.
A Toprol XL tablet can be divided in half if your doctor has told you to do so. The half tablet should be swallowed whole, without chewing or crushing.
While using metoprolol, you may need frequent blood tests at your doctor’s office. Your blood pressure will need to be checked often.
ENCOURAGE YOURSELF: SVT has no age restrictions. My suggestion to you, is to seek medical attention. Eat right, get plenty of rest, no alcohol, no smoking, as much exercise as your body will allow you to do. Must of all, don’t forget to pray.