Bezold Jarisch reflex

Bezold-Jarisch reflex
Synonyms	N/A
Pronounce	N/A
Specialty	N/A
Symptoms	Bradycardia, hypotension, vasodilation
Complications	N/A
Onset	N/A
Duration	N/A
Types	N/A
Causes	Activation of cardiac sensory receptors
Risks	N/A
Diagnosis	N/A
Differential diagnosis	N/A
Prevention	N/A
Treatment	Volume expansion, atropine
Medication	N/A
Prognosis	N/A
Frequency	N/A
Deaths	N/A

The Bezold-Jarisch reflex is a cardiovascular reflex characterized by a triad of responses: bradycardia, hypotension, and peripheral vasodilation. This reflex is triggered by the activation of sensory receptors located in the heart, particularly in the ventricles. It is named after Albert von Bezold and Adolf Jarisch, who first described the phenomenon in the late 19th and early 20th centuries.

Physiology

The Bezold-Jarisch reflex is mediated by the activation of chemoreceptors and mechanoreceptors in the heart, which send afferent signals via the vagus nerve to the central nervous system. These signals result in increased parasympathetic activity and decreased sympathetic activity, leading to the characteristic responses of the reflex.

Mechanism

1. Receptor Activation: The reflex is initiated by the stimulation of cardiac sensory receptors, which can occur due to various factors such as myocardial ischemia, hypoxia, or certain pharmacological agents.

2. Afferent Pathway: The sensory information is transmitted to the brainstem through the vagus nerve, which is a key component of the parasympathetic nervous system.

3. Central Processing: In the brainstem, the information is processed, leading to an increase in parasympathetic outflow and a decrease in sympathetic outflow.

4. Efferent Response: The efferent response results in bradycardia (slowing of the heart rate), hypotension (lowering of blood pressure), and vasodilation (widening of blood vessels).

Clinical Significance

The Bezold-Jarisch reflex can have significant clinical implications, particularly in situations such as:

• Myocardial Infarction: During a heart attack, the reflex may be activated due to ischemia, leading to bradycardia and hypotension, which can complicate the clinical picture.

• Anesthesia: Certain anesthetic agents can trigger the reflex, resulting in sudden drops in heart rate and blood pressure during surgical procedures.

• Orthostatic Stress: The reflex may play a role in the body's response to changes in posture, particularly in conditions like orthostatic hypotension.

Management

Management of the Bezold-Jarisch reflex involves addressing the underlying cause and may include:

• Volume Expansion: Administering intravenous fluids to increase blood volume and counteract hypotension.

• Atropine: An anticholinergic drug that can block the effects of increased parasympathetic activity, thereby increasing heart rate.

Research and Controversies

Research into the Bezold-Jarisch reflex continues to explore its role in various cardiovascular conditions and its potential therapeutic implications. Some controversies exist regarding the exact mechanisms and clinical relevance of the reflex in different scenarios.

Also see

• Vasovagal syncope
• Baroreceptor reflex
• Cardiac reflexes
• Autonomic nervous system

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