The risk of experiencing an irregular heartbeat (arrhythmia) increases with age and most people over the age of 75 years experience irregular heartbeats at some point. Not all irregular heartbeats are bad or need treatment. Factors that determine if an arrhythmia is clinically significant include: duration, arrhythmia type, underlying risk factors or trigger(s), and associated symptoms. Risk factors for heart arrhythmia, like atrial fibrillation (AFib) and atrial flutter, may be modifiable (i.e. high blood pressure, obesity, sleep apnea, etc.) or non-modifiable (age, family history, and gender).
Atrial fibrillation (AFib) is the most common sustained arrhythmia and is our primary focus at FixAfib. AFib and atrial flutter are arrhythmias that originate in the heart’s upper chambers (atria). Arrhythmia can also originate in the heart’s lower chambers (ventricles). Sustained ventricular arrhythmias are less common than atrial arrhythmias but can cause serious problems and can be life-threatening if they are not corrected.
By treating risk factors for heart arrhythmia you can make arrhythmias less likely to occur, slow disease progression, or make arrhythmia treatments more effective.
Since atrial fibrillation is the most common sustained arrhythmia, atrial fibrillation risk factors are reviewed here in detail. AFib risk factors include certain characteristics, health conditions and lifestyle choices that increase the risk of developing AFib. Risk factors for atrial fibrillation include:
People with heart disease are most at risk for developing an arrhythmia. Conditions that can damage the heart’s structure and cause heart disease include:
Transient conditions or insults can also put additional strain on the heart and can cause arrhythmias, including:
The normal heart rhythm is called normal sinus rhythm. Normal sinus rhythm occurs when the sinus node, which is the heart’s internal pacemaker, emits regular electrical impulses 60-100 times per minute. These electrical signals travel throughout the atria before moving on to the ventricles. This results in a coordinated, regular heart rhythm. Atrial fibrillation and atrial flutter occur when electrical signals from other areas of the atria override the sinus node.
The exact mechanisms of AFib are not fully understood but it appears that increased levels of stress hormones and inflammation increase oxidative stress which causes changes within the heart at the cellular level. These changes result in fibrosis (stiffening) and heart chamber enlargement which changes atrial function and creates an environment that is conducive to the initiation and maintenance of atrial fibrillation. The risk factors and conditions described above can all contribute to increased levels of inflammation and stress hormones which strain the heart.
In addition to the indirect effects of systemic inflammation and stress hormones, some conditions like heart disease, sleep apnea, and high blood pressure directly impact the heart’s structure and function to trigger AFib.
Ventricular arrhythmias. The left lower heart chamber (ventricle) is the workhorse of the heart and when the left ventricle contracts it ejects blood from the heart to the rest of the body. Normally, the heartbeat starts in the sinus node, which is located in the upper right heart chamber (atria) and is the heart’s internal pacemaker. The cardiac cycle (heart beat) starts when the sinus node generates an electrical impulse that spreads first throughout the atria and then the ventricles. This organized depolarization – atria, then ventricles – causes the heart muscle to contract to pump blood through and out of the heart and is what creates the typical regular heart rhythm.
In the case of a ventricular arrhythmia, the electrical impulse starts from somewhere within the ventricles which causes the heart contraction to start at the bottom of the heart and spreads upward. Ventricular beats tend to start earlier in the cardiac cycle when the heart should be between beats and thus filling with blood in preparation for the next contraction. Single early ventricular beats are very common and their frequency increases with age. An occasional, isolated premature ventricular contraction (PVC) is not dangerous but can cause symptoms which can include:
Heart palpitations have been described as feeling like a skipped beat, a flip-flop sensation in the chest, heart thumping/pounding, or a heart flutter. For some people, these early beats are very symptomatic and bothersome and in these cases, medications can be given to suppress the early beats.
If you have frequent symptomatic PVCs, your provider may want to order cardiac diagnostic tests to look for underlying causes that require treatment like heart failure, uncontrolled high blood pressure, sleep apnea, and coronary heart disease. Blood work will be checked for abnormalities that can contribute to frequent PVCs. Underlying health conditions that can trigger PVCs should be treated.
While isolated, occasional PVCs in the absence of heart disease are generally not concerning, a sustained ventricular arrhythmia can be dangerous and warrants further investigation to identify and treat underlying causes. A sustained ventricular arrhythmia can be life-threatening and is a medical emergency. Sustained ventricular arrhythmias include:
If you have heart palpitations or symptoms that are concerning for heart arrhythmia, you should contact your provider for further evaluation. Accurate diagnosis and effective treatment is important to help minimize the impact of a heart arrhythmia on your health and quality of life.