Palpitations and Cardiac Arrhythmias
Most people occasionally feel heart flutters or the heart skipping a beat or two – especially after exertion, during stress, or upon drinking caffeinated or alcoholic beverages. Palpitations are not unusual and for the most part inconsequential. But there are some arrhythmia conditions that can be life-threatening.
Palpitations only come to our attention when the heart’s electrical system misfires, so to speak. With normal rhythms, the heart beats about 60 to 80 times a minute when the heart’s natural pacemaker, the sinoatrial (SA) node, fires electrical impulses to the atrial muscle cells and to the atrio-ventricular (AV) node, which after a slight delay, fires signals to the ventricles. Any “short circuit” of sorts can cause abnormal firings and palpitations – either in separate beats or as clusters of beats that can go on for hours and even indefinitely if not treated.
There are different conditions that can lead to palpitations and more serious heart arrhythmias. As a rule, atrial palpitations are less serious than ventricular palpitations.
- Premature atrial and ventricular contractions (PACs and PVCs). In most cases, these irregular heartbeats are considered non-threatening when they occur occasionally in an isolated manner. Both involve electrical signals firing too soon, causing a palpitation. However, PVCs can signal underlying heart disease that if untreated can lead to sudden death.
- Atrial Fibrillation is one of the most common types of arrhythmias and is not considered life-threatening. It occurs when there is a rapid misfiring of electrical impulses in the atria and consequently in the ventricles as well. The heartbeat becomes fast and chaotic and the patient becomes easily fatigued with shortness of breath. Atrial fibrillation that last more than a day or more can increase the risk of stroke, since the abnormal pumping can form blood clots in the atria. Clots breaking free can flow to the brain.
- Tachycardia is when the heart rate becomes increased – sometimes at an alarming rate. There are two types: supraventricular tachycardia (SVT), which is atrial based; and ventricular tachycardia (VT) which can interfere with proper ventricular contraction. SVT usually is random and quickly begins and ends, while the more dangerous VT can significantly reduce the amount of blood pumped throughout the body and can sometimes result in loss of consciousness or sudden death. Closely related to VT, ventricular fibrillation (VF) is a serious form of heart failure that can cause fainting within seconds and consequent death if CPR is not immediately administered.
- Bradycardia is when the heart beat rate becomes greatly reduced resulting in no symptoms in mild cases, to dizziness or fainting. This condition is often due to disease in the SA and AV nodes, causing a loss of electrical impulses to the heart muscle.
Arrhythmias are detected while listening with a stethoscope or by EKG exams. In addition, a Holter monitor, worn for 24 to 48 hours, is used to record heartbeat activity during that period of time so physicians can assess any continuous arrhythmias.
MDCA cardiologists are specialists in assessing arrhythmias and providing treatment options. Medications including beta blockers and calcium channel blockers are often effective for keeping heart rhythms steady and strong. Pacemakers, hooked up to the heart’s right atrium and ventricle, can adjust rhythm abnormalities by shooting timed electrical impulses into the heart. Implantable defibrillators are lifesaving devices – restoring heartbeat by administering a shock after a sudden bout of ventricular fibrillation (VF). Invasive ablation procedures performed with special catheters, if successful, can completely cure certain arrhythmias by disrupting abnormal electrical flows within the heart.