“I had it once and I do not want to have it again ever in my life,” says Tameena Ali, a 32-year-old media personnel from Kolkata.
2017 was a stressful year for Ali. It began with a faint pain in her chest which she dismissed as acidity. But soon it started to intensify and radiate down her left hand.
Her ECG report turned out normal, and this baffled even her doctor. But due to her recurring bouts of breathlessness, sweating and vomiting, she was asked to take an ambulatory electrocardiogram (ECG), with a Holter monitor (a wearable device) for continuous monitoring of her heart rate.
“I had the device on me for 24 hours and it recorded that my heart rate would be higher during a certain time of the day – sometimes as high as 135 to 140 beats per minute (bpm),” she says.
Though Ali always had a slightly faster heart rate than normal (110-115 bpm), she never had such physical manifestations before.
She was diagnosed with supraventricular tachycardia which causes the heart to beat faster due to arrhythmia (altered heart rhythm). She was prescribed medications and instructed to adopt a healthier lifestyle. With regular simple physical exercise combined with dietary changes, she was able to bring down the frequency of medication and was taken off medication within five months. She has not had an episode since.
Supraventricular tachycardia is a common condition that occurs due to altered heart rhythm in the upper heart chamber. It rarely develops into a serious health complication. However, there are types of tachycardia which if left undiagnosed and unaddressed could even trigger a heart attack.
What is normal heartbeat
The heart pumps blood to various parts of the body. This happens when electrical impulses generated from the Sino Atrial (SA) node make muscles in the four heart chambers to contract and all four heart valves to open and close in a synchronised manner to ensure uni-directional blood flow. The SA node is also called the natural pacemaker of the heart.
The rate of contraction of these muscles is called heart rate (heartbeat) and the normal pattern of these electrical impulses is what is known as heart rhythm. Whenever there is a blip in the heart rhythm it will affect the heart rate forcing the heart to beat either slower or faster than the normal rate. Dr MS Meenakshi, interventional cardiologist, Fortis Hospital, Chennai, points out that for any adult, the normal heart rate is between 60 and 100 beats per minute under normal conditions.
Arrhythmia is the umbrella term for irregular heart rhythms and if the heart is beating at a faster rate and a slower rate than normal, it is called tachycardia and bradycardia respectively.
How serious is a heart arrhythmia?
Most of the time if there is a minor change in the heart rate, people might not even notice it. However, occasional fluctuations in the heart rate require a visit to the doctor as it could be due to sustained abnormal heart rhythm.
Ventricular tachycardia and atrial tachycardia
According to Dr Meenakshi, electrical impulses powering our heart originate in the two upper chambers (atria) and pass down to the two lower chambers (ventricles) from the SA node making all four heart valves to open and close in a fixed pattern to ensure blood flow in our body.
“There may be an increase in the heart rate when this pattern is not followed, and this condition is called tachycardia. When upper heart chambers beat three to five times more than it is supposed to, it is called atrial tachycardia,” she says.
Dr Meenakshi also adds that it is not mostly life-threatening as the contraction rates in the lower chambers (ventricles) compensate for it to avoid any disruption in our heart function.
“If the upper chamber beats 240 times, the lower chamber beats almost half the number of those beats, about 120 beats,” she says.
Unlike atrial tachycardia, ventricular tachycardia or irregularity in the lower chamber of the heart could lead to serious health complications. Sometimes, the lower chamber beats on its own as the heart muscles may be irritable and start misfiring electrical impulses, leading to its ineffective contraction and affecting the blood supply in the body including the brain.
“If there is no efficient blood supply to the brain, the person can collapse in 30 seconds and within a minute or two, could pass away,” she says.
Experts also point out that having a higher heart rate doesn’t essentially mean there are any heart complications. It needs to be checked only if there is a considerable variation in the heartbeats without any valid reason.
Dr Sunil Chandy, former director, CMC, Vellore, says, “You can have tachycardia, which is non-sustained. To call it tachycardia, the heart should have at least three abnormal beats. When it exceeds that, you can go into sustained tachycardia, which is when the problem of the blood supply comes. It is difficult to sustain the blood flow from the heart because of at least three extra heartbeats.”
What causes ventricular tachycardia?
Ventricular tachycardia is more common in people with existing heart disease, especially among those above 35 years.
“Higher the age, higher the risk. It can be managed with early intervention possibly through lifelong medications,” says Dr Chandy.
Some high-risk factors for ventricular tachycardia are:
- Heart attack
- Cardiomyopathy
- Congenital heart disease
- Excessive exercises
- Blunt cardiac injury
Why are people collapsing in gym?
Undiagnosed heart problems or underlying heart conditions are often heart attack catalysts, especially from over-physical exertion and unsupervised rigorous workout sessions. This combined with severe deviations in heart rhythm either, tachycardia (fast heart rate) or bradycardia (slow rate) could have serious health consequences. Dr Chandy points out that exercise and physical activity change our heart rate but if we have a healthy heart it will recover. However, when this does not happen then the individual could suffer a heart failure.
“If your heart is healthy, it recovers faster (within three minutes) after the workout. If you have a prolonged heart illness, the heart rate recovery will take longer,” says Dr Chandy.
Massive blunt trauma or injury to the chest could also hamper the blood flow from the heart to the brain as the shock from these incidents could scramble the electrical impulses leading to a sudden alteration in heart rhythm cutting off the blood supply. This is very common during collisions and close-contact sports; it could even affect perfectly healthy athletes.
“It can knock off the brain in a minute. If the basic life support is not provided immediately with chest compressions or CPR, one may not survive,” Dr Chandy says.
Ventricular tachycardia symptoms
Frequent bouts of sudden unconsciousness spells, giddiness, nausea, breathlessness etc are the main symptoms of ventricular tachycardia, Dr Chandy points out. If there is neither medical nor physical explanation for these episodes, then one should seek medical help, he adds.
He suggests the following tips to avoid sudden cardiac emergencies due to ventricular tachycardia:
- Get the cause of the disease corrected if correctible
- Follow regular check-ups
- Avoid solo travel trips
- Keep diabetes and blood pressure under check
- Avoid strenuous workouts
What is the best treatment for ventricular tachycardia?
People with recurrent ventricular tachycardia episodes are often asked to get AICD (automatic implantable cardioverter-defibrillator) implanted. “They are like the miniature version of the shock paddles used to resuscitate the heart in the hospital. AICD can be inserted like a pacemaker, which is programmed to sense ventricular tachycardia. If the heart rate goes more than 200, it can sense and trigger a shock and it will get okay,” he says.
2 Responses
Nice and useful article. I have also undergone EPS followed by RFA in 1999.
Excellent article. Very informative. With the rising number of heart attacks, especially among the young, information leading to the understanding of tell tale symptoms will go a long way in seeking timely help.