Bradycardia

Bradycardia is a medical term used to describe a slower than normal heart rate. In adults, a resting heart rate of fewer than 60 beats per minute often qualifies as bradycardia. This condition can be a symptom of underlying health issues, or a side effect of certain medications, but it is also commonly observed in trained athletes with efficient cardiovascular systems.

Lead II rhythm generated sinus bradycardia

Definition and Classification

Bradycardia is typically defined as a resting heart rate under 60 beats per minute (bpm) in adults. It's important to note that a slow heart rate is not inherently problematic and does not always indicate a medical condition. For example, well-conditioned athletes often exhibit bradycardia, as physical training makes the heart more efficient.

Causes

Bradycardia can result from a variety of causes, including:

• Heart Disease: Conditions that damage the heart’s electrical system can slow the heart rate.
• Hypothyroidism: An underactive thyroid can cause a slow heart rate.
• Electrolyte Imbalance: Imbalances in electrolyte levels, particularly potassium and calcium, can affect the heart's electrical signaling.
• Medications: Certain drugs, such as beta-blockers and some heart medications, can cause bradycardia.

Error creating thumbnail:

12 lead sinus bradycardia

Symptoms and Complications

While bradycardia itself often doesn't cause symptoms, if the heart isn't pumping enough oxygen-rich blood to the body, symptoms may occur. These can include fatigue, weakness, dizziness, shortness of breath, or fainting. In severe cases, it can lead to cardiac arrest.

Diagnosis and Treatment

Diagnosis of bradycardia typically involves a physical examination, patient history, and the use of an electrocardiogram (ECG) to measure the heart's electrical activity. If necessary, a Holter monitor may be used to record the heart's activity over 24 hours.

Treatment of bradycardia depends on its underlying cause. If medication is the cause, adjusting or changing the medication can resolve the issue. If a physical condition is causing bradycardia, treating that condition can alleviate the bradycardia. In some cases, the installation of a pacemaker might be required to regulate the heart rate.

References

Bradycardia Resources
Latest articles Most recent articles Ongoing trials	Wikipedia

Cardiovascular disease A-Z

Most common cardiac diseases

• Cardiac arrhythmia‎
• Cardiogenetic disorders‎
• Cardiomegaly‎
• Cardiomyopathy‎
• Cardiopulmonary resuscitation‎
• Chronic rheumatic heart diseases‎
• Congenital heart defects‎
• Heart neoplasia‎
• Ischemic heart diseases‎
• Pericardial disorders
• Syndromes affecting the heart‎
• Valvular heart disease‎

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

A

• Accelerated idioventricular rhythm
• Acute decompensated heart failure
• Arteriosclerotic heart disease
• Athletic heart syndrome
• Atrial flutter
• Atrioventricular fistula
• Cardiovascular disease in Australia
• Autoimmune heart disease

B

• Brown atrophy of the heart

C

• Ebb Cade
• Cardiac allograft vasculopathy
• Cardiac amyloidosis
• Cardiac asthma
• Cardiac tamponade
• Cardiogenic shock
• Cardiogeriatrics
• Cardiorenal syndrome
• Cardiotoxicity
• Carditis
• Coronary artery aneurysm
• Coronary artery anomaly
• Coronary artery disease
• Spontaneous coronary artery dissection
• Coronary artery ectasia
• Coronary occlusion
• Coronary steal
• Coronary thrombosis
• Coronary vasospasm
• Cœur en sabot
• Coxsackievirus-induced cardiomyopathy

D

• Duke Treadmill Score
• Duroziez's disease

E

• Eisenmenger's syndrome
• Embryocardia
• Endocardial fibroelastosis
• Eosinophilic myocarditis

H

• Heart attack
• Heart failure
• Heart failure with preserved ejection fraction
• Heart to Heart (1949 film)
• High-output heart failure
• Hyperdynamic precordium

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

I

• Idiopathic giant-cell myocarditis
• Interventricular dyssynchrony
• Intraventricular dyssynchrony
• Isolated atrial amyloidosis

K

• Keshan disease

L

• Loeffler endocarditis

M

• Mydicar
• Myocardial bridge
• Myocardial disarray
• Myocardial rupture
• Myocardial scarring
• Myocardial stunning
• Myocarditis

N

• Nonbacterial thrombotic endocarditis

O

• OLR1
• Ostial disease

P

• Papillary fibroelastoma
• Pathophysiology of heart failure
• Postpericardiotomy syndrome
• Pulmonary vein stenosis

R

• Right axis deviation
• Roemheld syndrome

S

• Saturated fat and cardiovascular disease
• SCAR-Fc
• Shone's syndrome
• Strain pattern
• Subacute bacterial endocarditis
• Sudden cardiac death of athletes

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z

T

• Traumatic cardiac arrest

V

• Ventricular aneurysm
• Vibroacoustic disease
• Viral cardiomyopathy

W

• Waon therapy