Catecholaminergic polymorphic ventricular tachycardia
Encyclopedia
Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is an electrophysiological disorder of the heart
that occurs in genetically predisposed
individuals. Thought to affect as many as one in ten thousand people, it is estimated to cause 15% of all unexplained sudden cardiac death
s in young people.
First recognized in 1975, the voltage gated ion channel mutation intermittently causes the heart to enter a life threatening
state of arrhythmia as response to the natural release of catecholamines. The most common symptom is syncope
, which most commonly appears during the first or second decade of life.
Because its symptoms are most prevalent when the body is subjected to intense emotional or physical stress, the condition can elude traditional methods of heart examination such as echocardiogram and resting electrocardiogram
.
.
According to recent research published in Nature Medicine
, flecainide
inhibits the release of the cardiac ryanodine receptor–mediated Ca2+, and is therefore believed to medicate the underlying molecular cause of CPVT in both mice and humans.
s are used to prevent sudden death
.
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
that occurs in genetically predisposed
Genetic predisposition
A genetic predisposition is a genetic affectation which influences the phenotype of an individual organism within a species or population but by definition that phenotype can also be modified by the environmental conditions. In the rest of the population, conditions cannot have that effect...
individuals. Thought to affect as many as one in ten thousand people, it is estimated to cause 15% of all unexplained sudden cardiac death
Sudden Cardiac Death
Sudden cardiac death is natural death from cardiac causes, heralded by abrupt loss of consciousness within one hour of the onset of acute symptoms. Other forms of sudden death may be noncardiac in origin...
s in young people.
First recognized in 1975, the voltage gated ion channel mutation intermittently causes the heart to enter a life threatening
Medical emergency
A medical emergency is an injury or illness that is acute and poses an immediate risk to a person's life or long term health. These emergencies may require assistance from another person, who should ideally be suitably qualified to do so, although some of these emergencies can be dealt with by the...
state of arrhythmia as response to the natural release of catecholamines. The most common symptom is syncope
Syncope (medicine)
Syncope , the medical term for fainting, is precisely defined as a transient loss of consciousness and postural tone characterized by rapid onset, short duration, and spontaneous recovery due to global cerebral hypoperfusion that most often results from hypotension.Many forms of syncope are...
, which most commonly appears during the first or second decade of life.
Because its symptoms are most prevalent when the body is subjected to intense emotional or physical stress, the condition can elude traditional methods of heart examination such as echocardiogram and resting electrocardiogram
Electrocardiogram
Electrocardiography is a transthoracic interpretation of the electrical activity of the heart over a period of time, as detected by electrodes attached to the outer surface of the skin and recorded by a device external to the body...
.
Syncopal
CPVT may cause exercise-induced ventricular arrhythmias and/or syncope occurring during physical activity or acute emotion, but demonstrates no structural problems of the heart. Ventricular tachycardia may self-terminate or degenerate into ventricular fibrillation, causing sudden death without immediate cardiopulmonary resuscitation. The majority of events occur during childhood and more than 60% of affected individuals will have a first episode of syncope or cardiac arrest by age 20.Diagnosis
CPVT diagnosis is based on reproducing ventricular arrhythmias during exercise stress testing, syncope occurring during physical activity and acute emotion, and a history of exercise or emotion-related palpitations and dizziness with an absence of structural cardiac abnormalities.| Type | OMIM | Gene | Locus |
|---|---|---|---|
| CPVT1 | RYR2 | 1q42.1-q43 | |
| CPVT2 | CASQ2 | 1p13.3-p11 |
- The Ryanodine receptor (RYR2) is involved in intracardiac Ca2+ handling; Ca2+ overload triggers abnormal cardiac activity.
- Calsequestrin (CASQ2) is a calcium buffering protein of the sarcoplasmic reticulum.
Medication
Medications to treat CPVT include beta blockers and verapamilVerapamil
Verapamil is an L-type calcium channel blocker of the phenylalkylamine class. It has been used in the treatment of hypertension, angina pectoris, cardiac arrhythmia, and most recently, cluster headaches. It is also an effective preventive medication for migraine...
.
According to recent research published in Nature Medicine
Nature Medicine
Nature Medicine is an academic journal publishing research articles, reviews, news and commentaries in the biomedical area, including both basic research and early-phase clinical research. Topics covered include cancer, cardiovascular disease, gene therapy, immunology, vaccines, and neuroscience...
, flecainide
Flecainide
Flecainide acetate is a class Ic antiarrhythmic agent used to prevent and treat tachyarrhythmias . It is used to treat a variety of cardiac arrhythmias including paroxysmal atrial fibrillation , paroxysmal supraventricular tachycardia Flecainide acetate is a class Ic antiarrhythmic agent used to...
inhibits the release of the cardiac ryanodine receptor–mediated Ca2+, and is therefore believed to medicate the underlying molecular cause of CPVT in both mice and humans.
Implantable cardioverter-defibrillator
Implantable cardioverter-defibrillatorImplantable cardioverter-defibrillator
An implantable cardioverter-defibrillator is a small battery-powered electrical impulse generator which is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia. The device is programmed to detect cardiac arrhythmia and correct it...
s are used to prevent sudden death
Sudden death
In a sport or game, sudden death is a form of competition where play ends as soon as one competitor is ahead of the others, with that competitor becoming the winner. Sudden death is typically used as a tiebreaker when a contest is tied at the end of the normal playing time or the completion of...
.
Sympathectomy
In recent reports, left cardiac sympathetic denervation and bilateral thoracoscopic sympathectomy have shown promising results in individuals whose symptoms cannot be controlled by beta blockers.See also
- Brugada syndromeBrugada syndromeThe Brugada syndrome is a genetic disease that is characterised by abnormal electrocardiogram findings and an increased risk of sudden cardiac death. It is named by the Spanish cardiologists Pedro Brugada and Josep Brugada...
- Cardiac arrhythmia
- Long QT syndromeLong QT syndromeThe long QT syndrome is a rare inborn heart condition in which delayed repolarization of the heart following a heartbeat increases the risk of episodes of torsade de pointes . These episodes may lead to palpitations, fainting and sudden death due to ventricular fibrillation...
- Sick sinus syndromeSick sinus syndromeSick sinus syndrome, also called sinus node dysfunction, is a group of abnormal heart rhythms presumably caused by a malfunction of the sinus node, the heart's primary pacemaker...
- Sudden cardiac deathSudden Cardiac DeathSudden cardiac death is natural death from cardiac causes, heralded by abrupt loss of consciousness within one hour of the onset of acute symptoms. Other forms of sudden death may be noncardiac in origin...
Further reading
- Receptor defects cause inherited disorder CPVT
- Denervation successfully treats catecholaminergic polymorphic ventricular tachycardia
- Screening relatives of sudden-death victims provides likely cause of death and potentially saves lives
- Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) Information sheet - Auckland District Health Board's Cardiac Inherited Disease Registry
- Clinical Data's PGxHealth Division Launches CPVT Cardiac Channelopathy Test - Business Wire
- SADS UK - What is CPVT
- Arrhythmogenesis in CPVT: Lessons Learned from a CPVT Mouse Model