Heart Arrhythmias

Original Editor - Vidya Acharya Top Contributors - Vidya Acharya and Lucinda hampton

Introduction[edit | edit source]

Normal conduction system of the heart

Arrhythmia are a broad spectrum of disorders of heart rate and rhythm abnormalities. Arrhythmia is broadly categorized into bradyarrhythmias (heart rate of fewer than 60 beats per minute) and tachyarrhythmia (heart rate higher than 100 bpm). Patients with an arrhythmia may exhibit a broad spectrum of clinical presentation from being entirely asymptomatic to sudden cardiac arrest. [1]

The only normal rhythm of the heart is a normal sinus rhythm. In this rhythm, an impulse is generated in the sinoatrial (SA) node, which is conducted through and slowed down while passing through the atrioventricular node (AV). It is then passes through the bundle of His, to the left and right bundle branches, and eventually into the Purkinje fibers.[2]See image.

Epidemiology[edit | edit source]

The prevalence of arrhythmias is expected to be 1.5% to 5% in the general population, with atrial fibrillation being the most common. Arrhythmias may or may not produce any symptoms and can be paroxysmal, leading to difficulty in estimating true prevalence. The overall presence of arrhythmia is associated with higher morbidity and mortality.

  • 1 in 10 Australians die suddenly due to an abnormal heart rhythm, this occurs most commonly just after a heart attack.
  • About 200 young Australians under 18 die each year as a result of cardiac arrhythmia. Half of these people will be unaware of an underlying issue[1]. [3]

Etiology[edit | edit source]

Heart Attack

There are a number of factors that can cause a heart arrhythmia, including: Heart attack or scarring of the heart tissue from a heart attack; Coronary heart disease; High blood pressure; Smoking; Genetics; Changes to the heart’s structure e.g. from cardiomyopathy; Diabetes; Sleep apnea; Some medication; Alcohol abuse; Excessive caffeine consumption; Overactive thyroid gland (hyperthyroidism); Underactive thyroid gland (hypothyroidism); Drug abuse; Stress.[3]

Arrhythmia Types[edit | edit source]

Cardiac Arrhythmias

Include:

  1. Atrial fibrillation: an irregular and often rapid heart rate. The heartbeat of a patient with atrial fibrillation is typically about 150 beats per minute but can reach 350 beats per minute in extreme cases.
  2. Atrial flutter (AFL): the atria beat regularly but too fast, which results in atrial muscle contractions that are faster and out of sync with the lower chambers or ventricles, of the heart. Patients with AFL typically experience heart rates of 150-180 beats per minute at rest, but rarely can reach 300-350 beats per minute.
  3. Supraventricular tachycardia (SVT): rapid heartbeat caused by faulty electrical signals in the upper parts of the heart. Patients usually experience a burst of accelerated heartbeats. SVT usually affects young, healthy people, who will experience a heart rate between 160 and 200 beats per minute.
  4. Ventricular tachycardia: an abnormal electrical impulse that begins in the ventricles and causes an irregular fast heartbeat. The ventricle will often contract more than 200 times a minute.
  5. Ventricular fibrillation: occurs when rapid and erratic electrical impulses cause the ventricles to quiver instead of pump blood properly. It is life-threatening and is often triggered by a heart attack.
  6. Long QT syndrome (LQT): causes uncoordinated heartbeats which can lead to sudden, uncontrollable and dangerous arrhythmias. Patients with LQT syndrome have an underlying genetic problem.
  7. Bradycardia: heart beats too slow – under 60 beats per minute. It is a normal phenomenon in people who are very fit (e.g. professional athletes). Bradycardia is however a problem if as a result there is not enough blood reaching the brain, causing fainting.
  8. Ectopic beats; extra heart beats that can arise from the atria (atrial ectopic beats) or ventricles (ventricular ectopic beats). These extra beats are usually silent but occasionally,  people will notice that their heart appears to have “skipped” a beat or had an extra strong beat. Ectopic beats are almost always benign[3].

Presentation[edit | edit source]

Symptomatology comprises fainting, lightheadedness, chest pain, palpitations and shortness of breath.[4]

Assessment[edit | edit source]

A proper medical history, family history, and physical examination should be carried out by the doctor. The clinician checks for :

  • swelling in your legs or feet (an enlarged heart or heart failure)
  • pulse rate
  • rate and rhythm of the heartbeat
  • heart murmur
  • signs of other diseases, such as thyroid disease, that could be causing the arrhythmia

Diagnostic Tests[edit | edit source]

ECG Waves.png

Electrocardiogram: simple non-invasive test that records the heart's electrical activity[5]. The ECG produces a printout that doctors can examine to diagnose arrhythmias or other types of heart disease. ECG can accurately diagnose atrial fibrillation.[6]

Blood tests: carried out to check electrolytes and levels of thyroid functions. Risk of arrhythmias increases with an overactive thyroid gland or with an electrolyte imbalance[6].

Holter monitors: Called as ambulatory electrocardiograms. They are battery-operated portable devices that record the heart’s activity (ECG) continuously for 24 to 48 hours or longer depending on monitoring requirements. Small electrodes along with wires are attached to the skin[7].

Event Recorders: A cardiac event recorder helps in recording the electrical signals of the heart while carrying out daily activities. It is a battery-powered portable device that records the heart’s electrical activity (ECG) when an individual has symptoms. They are also called ambulatory ECG monitors.[8] Event Recorder only records when it is activated or when the abnormal heart rhythm is detected. These can be worn for a month or longer.[9] There are two types of recorders: a loop memory monitor and a symptom event monitor.

Echocardiogram: An echocardiogram uses ultrasound waves to detect the heart’s size, structure, and motion. The most common type of echocardiogram is transthoracic echocardiography (TTE) provides valuable information about a heart with an arrhythmia[10].

Stress Test: Also called treadmill test or an exercise stress test, can diagnose people suspected with exercise-related arrhythmias[10].

Electrophysiology study (EPS): can help to investigate suspected arrhythmias. This procedure can provoke and diagnose known as well as infrequent arrhythmias and also help trigger latent tachycardia (fast heart rate) or bradycardia (slow heart rate)[10].

Head-up tilt table test: carried out in cases of dizziness or fainting spells. The test tells about how heart rate and blood pressure respond while changing positions from lying down to standing up. An abnormally slow heart rate or a fast heart rate can cause a drop in blood pressure with the table tilted upwards. The test is normal if average blood pressure stays stable as the table tilts upward and the heart rate increases by a normal amount[10].

Treatment[edit | edit source]

Treatment is only necessary if symptoms are severe, or if client is at risk of a more serious arrhythmia or complication. Possible treatments include: Pacemaker; Medications; Cardioversion; Catheter ablation; Implantable cardioverter-defibrillator (ICD); Surgical procedure to disrupt abnormal electrical circuits (Maze procedure); Coronary bypass surgery

Alternative medicine including yoga, meditation or relaxation techniques.[3]

Physiotherapy[edit | edit source]

Yoga

Ample evidence indicates that moderate regular exercise is beneficial for both normal individuals and patients with cardiovascular (CV) disease. However, intense and strenuous exercise in individuals with arrhythmias. They may have adverse effects with provocation and exacerbation of arrhythmias that may lead to life-threatening situations.[11]

The type and amount of exercise that is allowable will vary depending on the cause of the arrhythmia and other forms of heart disease exist.

The client/physiotherapist should talk with their doctor. He or she may do a physical exam, an electrocardiogram (EKG or ECG), and possibly a stress ECG test to assess what level of activity your heart can handle. Then an exercise plan can be formulated. An exercise program usually consists of stretching, activities that increase your heart rate (aerobic exercise), and strength training (lifting light weights).

Ensure the client knows their symptoms. eg stop exercising and get some rest if they develop palpitations, chest pain, or dizziness or lightheadedness.[12]

Suggest client joins a eg health club, walking group, yoga class. Senior centers often offer exercise programs.[12]

Conclusion[edit | edit source]

Heart rate monitor.jpg

Arrhythmias can pose a diagnostic dilemma. The patient presentation can be varied even for the same arrhythmia and can require a different management approach based on the patient's clinical condition and characteristics[2].

Depending upon the type and severity of arrhythmias, the cardiologist may prescribe antiarrhythmic drugs, or surgical implant-devices or procedures to control the abnormal rhythm, and advice healthy lifestyle changes.

References[edit | edit source]

  1. 1.0 1.1 Desai DS, Hajouli S. Arrhythmias. StatPearls [Internet]. 2021 Jun 18.Available:https://www.ncbi.nlm.nih.gov/books/NBK558923/ (accessed 3.3.2022)
  2. 2.0 2.1 Desai DS, Hajouli S. Arrhythmias. StatPearls [Internet]. 2020 Jun 25.Available from:https://www.ncbi.nlm.nih.gov/books/NBK558923/ (last accessed 3.10.2020)
  3. 3.0 3.1 3.2 3.3 Victor Chang Arrhythmia Available: https://www.victorchang.edu.au/arrhythmia(accessed 3.3.2022)
  4. Radiopedia Arrhythmias Available:https://radiopaedia.org/articles/arrhythmia?lang=us (accessed 3.3.2022)
  5. The ECG leads: electrodes, limb leads, chest (precordial) leads, 12-Lead ECG (EKG).https://ecgwaves.com/ekg-ecg-leads-electrodes-systems-limb-chest-precordial/ accessed on 26/9/2020
  6. 6.0 6.1 Maharty DC. Atrial fibrillation overview.
  7. Holter Monitor.Accessed fromhttps://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack/holter-monitor on 26/09/20
  8. Arrythmias, Cardiac Event Recorder. Accessed on 25/9/2020 from https://www.heart.org/en/health-topics/arrhythmia/prevention--treatment-of-arrhythmia/cardiac-event-recorder
  9. John Hopkins Medicine, Health, Event Monitor. Accessed on 25/9/2020 fromhttps://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/event-monitor
  10. 10.0 10.1 10.2 10.3 Common Tests for Arrhythmia. Accessed on 27/9/2020 fromhttps://www.heart.org/en/health-topics/arrhythmia/symptoms-diagnosis--monitoring-of-arrhythmia/common-tests-for-arrhythmia
  11. Manolis AS, Manolis AA. Exercise and arrhythmias: a double‐edged sword. Pacing and Clinical Electrophysiology. 2016 Jul;39(7):748-62. Available: https://pubmed.ncbi.nlm.nih.gov/27120033/(accessed3.3.2022)
  12. 12.0 12.1 University of Michigan Heart Arrhythmias and Exercise Available:https://www.uofmhealth.org/health-library/te7480 (accessed 3.3.2022)