Ectopics / Missed Beats

If you’ve ever felt your heart “skip a beat,” it was probably from this early beat that disrupts the heart’s rhythm. In reality, the heart doesn’t skip a beat. Instead an extra beat comes sooner than normal. Then there’s usually a pause that causes the next beat to be more forceful. You felt this more-forceful beat.

• Premature atrial contractions (PACs) start in the upper chambers of the heart (atria).
• Premature ventricular contractions (PVCs) start in the lower chambers of the heart (ventricles).

Often, the cause of ectopic rhythm is unknown. Some of the factors that can cause or aggravate ectopic rhythm are:

Alcohol, caffeine, smoking, some prescribed medications / some illegal drugs (stimulants), high levels of adrenaline, usually due to stress, exercise

If the condition persists for a long time, it’s more likely that there’s an underlying condition, such as:

• Heart disease
• Chemical imbalance
• Injury to the heart muscle due to heart disease, infection, infarction or high blood pressure

• Palpitation
• Giddiness

• Electrocardiogram (ECG)
• 24 hours heart monitor (also known as a Holter monitor)
• External Loop Recorder [ELR]
• Echocardiogram
• Routine blood tests including Electrolytes and thyroid function test.

A 24hrs (or more prolonged) heart monitor can calculate the frequency and total burden of ectopics. More than that, it can determine whether the ectopics arise predominantly from one location in the heart or from several. For example, it is possible that all ectopics occur from a single site in a single chamber, or that they occur in multiple sites from the same chamber, or sometimes from multiple sites and/or multiple chambers.

• Avoid triggers
• Reduce alcohol, caffeine
• Switching to decaffeinated tea and coffee
• Avoiding fizzy drinks with caffeine (particularly energy drinks)
• Stop smoking
• Avoid or reduce stress
• Get more sleep
• Reassurance after appropriate tests
• Switching medications
• Treat an underlying condition causing Ectopics

The treatments above are unsuccessful and this occurs most often when people experience extremely high burdens of Ectopics i.e. they continuously occur every 2-10 beats. This usually means the cause of the ectopic isn’t stress-related, or temporary, but due to a cell or small group of cells in the heart continuously firing of their own accord. It is known this is often due to an abnormality of how cardiac cells handle calcium and this is why drugs called calcium channel blockers can often be helpful in suppressing these.

If medications aren‘t helpful in suppressing very frequent ectopics, and especially if there are continuous runs of Ectopics (known as ventricular tachycardia), a procedure called radiofrequency catheter ablation is offered.

Catheter ablation is a technique in which fine wires (catheters) are introduced to the heart via the veins at the top of the leg. The wires can then be used to create a 3D computer model of the inside of the chamber where the ectopics are arising. Information from the electrical signals recorded by the catheter during the ectopic beats helps identify where they originate. The catheter is then advanced to that location and energy delivered to the tip of the catheter causing it to heat up. The heat applied to the tissue causes destruction of this tissue (a very tiny area) and abolishes the ectopic.

The success of ablation depends largely on how frequently the ectopics are occurring at the time of ablation. The more frequent, the chance of success rate is high. In most cases the success rate of ablation is around 90% of a permanent cure. If ectopics are frequently present at the start of the procedure and are abolished during ablation and do not recur by the end of the procedure, this is usually a very good sign that they will not recur afterwards, although this can still happen in some cases.