Cardiac Arrhythmia

Cardiac Arrhythmia

Cardiac Arrhythmia

A Healthy Heart Rhythm

At rest, the heart beats to a regular rhythm 60 to 80 times per minute. This is called “sinus rhythm” because the upper heart chamber’s sinus node works as the heart’s “clock,” setting its rate and rhythm by generating electrical impulses. These electrical impulses spread through the walls of the upper and lower heart chambers. Irregularities in the sinus rhythm are called “impulse generation diseases.”
In the lower chambers, the impulses stimulate the heart muscles to contract and pump blood through the body. In times of physical or emotional stress, the body needs more oxygen-rich blood. To meet this demand, the nervous system accelerates the heartbeat. Irregularities of this kind are called “conduction system diseases.”
In cases of heart rhythm disorders (arrhythmias), the generation of electrical impulses, the heart’s contraction, or both can be disturbed.


What Are the Symptoms of Heart Rhythm Disorders?

Even the healthy heart can skip a beat. Usually you will not notice when this happens. Sometimes you will feel your heart beating irregularly. These are called “palpitations”. If you have no other symptoms, palpitations are usually harmless.
See your physician if an arrhythmia or unexplained fast heartbeat (tachycardia) occurs often. Visit a doctor as soon as possible if you experience dizziness or light pressure in the chest during an arrhythmia. Go to an emergency room immediately if you faint (syncope), experience cramping or chest pain.


How Are Heart Rhythm Disorders Diagnosed?

To diagnose a heart rhythm disorder (arrhythmia), a physician will ask questions about your medical history, what symptoms you experienced and how you felt leading up to and during the event. During a physical exam, the physician will listen to your heart rhythm, checking for any extra or unusual sounds (a heart murmur). He or she will also measure your heartrate (pulse). Then the physician will perform an electrocardiogram (ECG/EKG) while you are at rest, and during physical exercise. The ECG shoes the heart’s electrical activity, allowing the physician to tell what is causing the irregularities in your heartbeat.
A long-term ECG is necessary if the arrhythmias occur rarely. These devices record an ECG over a longer period:

  • A Holter monitor – a portable device that records an ECG continually for at least 24 hours.
  • An event recorder – activated by the patient when they feel an arrhythmia.
  • If the above methods do not show an arrhythmia, an implantable cardiac monitor (ICM) can be implanted to observe the heart’s rhythm over a longer period. BIOTRONIK’s cardiac monitor, BioMonitor 2, is inserted under the skin on your chest and monitors heart activity up to two years. BIOTRONIK Home Monitoring® sends daily recordings of this activity to your physician via a small transmitter, allowing them to recognise a cardiac arrhythmia and detect the causes of previously unexplained fainting (syncope episodes) quickly, or exclude cardiac arrhythmia as a cause.


What Kinds of Heart Rhythm Disorders Exist?

Disorders can exist in the heart’s generation of electrical impulses or contraction. Arrhythmias can occur in the upper and lower heart chambers. This distinction is crucial because arrhythmias of the lower chambers (ventricles) can be life-threatening events. Tachycardia is means the heart beats too quickly; bradycardia means the heart beats too slowly. Known types of arrhythmias include:

  • Extrasystole: isolated extra heartbeats that are mostly harmless.
  • Atrial flutter: fast contractions of the upper heart chambers (atria) with a regular pulse of 120 to 140 beats per minute.
  • Atrial fibrillation: very fast, chaotic activity in the upper heart chambers with an irregular pulse. Has a high risk of thromboembolism (the blocking of a blood vessel by a blood clot) and stroke.
  • Ventricular flutter (ventricular tachycardia): dangerous, very fast and regular contractions of the lower heart chambers. Occurs before ventricular fibrillation.
  • Ventricular fibrillation: life-threatening, very fast and chaotic activity in the upper and lower heart chambers without a pulse.
  • Bradycardia: the heart beats too slow at rest with 50 beats per minute or less. This can be normal for athletes.


What Causes Heart Rhythm Disorders?

Internal and external factors can lead to or cause cardiac arrhythmias. Some internal factors like fever are temporary. Others throw the heart out of its rhythm permanently.


External causes:

  • Stress, excitement, fear, nervousness
  • Caffeine (from energy drinks or coffee), alcohol, drugs, toxins
  • Specific medications (for example, thyroid hormones)
  • Pressure at a certain area of the carotid artery in the neck the heartbeat to slow until a patient faints or goes into cardiac arrest (carotid sinus reflex).


Temporary internal causes:

  • Fever and infections
  • Electrolyte disorders (for example, lack of potassium)


Permanent internal causes :

  • Coronary artery disease or heart attack
  • High blood pressure (hypertension)
  • Diseases and inflammations of the heart muscle (cardiomyopathy, myocarditis)
  • Heart malformations or valvular heart disease
  • Impulse generation or conduction system diseases (for example, Wolff-Parkinson-White-syndrome)
  • Thyroid diseases (hyperthyroidism, hypothyroidism)
  • Inherited genetic disorders affecting the electrolyte channels of the heart cells (for example, Long QT syndrome, Brugada syndrome - sometime called channelopathies)

Read more about treatment options in heart rhythm disorders.


Living With Heart Rhythm Disorders: What Patients Can Do

Take several breaks a day to relax and avoid stress. Certain exercises can help you to relax (for instance, yoga, relaxation therapy and meditation).

  • Refrain from smoking or drinking too much caffeine or alcohol. Your physician can advise you how to quit smoking.
  • Certain medications can trigger rhythm disorders. If you have to take medication, discuss the issue with your physician and to change medications or doses if necessary.
  • Go to all physical check-up appointments. Diseases such as hyperthyroidism can cause arrhythmia.
  • Pacemakers and Defibrillators need to be checked regularly. If you experience a problem with your device, a physician has to be consulted immediately.

Exercise is healthy. Be careful not to overexert yourself. Ask your physician what kind of exercise and at what intensity he or she recommends.