Catecholaminergic polymorphic ventricular tachycardia
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| Catecholaminergic polymorphic ventricular tachycardia | |
|---|---|
| Specialty | Cardiology  |
Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT) is a rhythm disorder of the lower chambers of the heart, or ventricles that occurs in genetically predisposed individuals. Synonyms: Familial Polymorphic Ventricular Tachycardia (FPVT), Catecholamine-Induced Polymorphic Ventricular Tachycardia. Thought to affect as many as one in ten thousand people, it is estimated to cause 15% of all unexplained sudden cardiac deaths in young people.
First recognized in 1975, this condition, due to a mutation in a voltage gated ion channel which regulates the flow of ions in and out or cardiac cells and therefore their electrical stability may cause the heart to enter a life threatening state of arrhythmia as response to the natural release of catecholamines from nerve endings on the heart muscle and from the adrenal glands into the circulation. This rhythm disturbance prevent the heart from pumping blood appropriately. The most common symptom is dizziness or syncope occurring on exercise or due to emotional stress, symptoms which typically starts manifesting themselves 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.[1][2][3][4]
Signs and symptoms
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Dizziness and Syncope
CPVT may cause exercise-induced ventricular arrhythmias with ensuing dizziness and/or syncope occurring during physical activity or acute emotional stress. Affected patients though demonstrate 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 irregularly shaped ventricular arrhythmias during ECG 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.[5]
| Type | OMIM | Gene | Locus |
|---|---|---|---|
| CPVT1 | Template:OMIM2 | RYR2 | 1q42.1-q43 |
| CPVT2 | Template:OMIM2 | CASQ2 | 1p13.3-p11 |
- The Ryanodine receptor (RYR2) is involved in intracardiac Ca2+ handling; Ca2+ overload triggers abnormal cardiac activity.[6]
- Calsequestrin (CASQ2) is a calcium buffering protein of the sarcoplasmic reticulum.
Inheritance
Mutation of RYR2 is inherited in an autosomal dominant fashion. The inheritance of the Calsequestrin-2 mutation is autosomal recessive.
Treatment
Medication
Medications to treat CPVT include beta blockers and verapamil.[7]
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.[8]
Implantable cardioverter-defibrillator
Implantable cardioverter-defibrillators are used to prevent sudden death.
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.[3][9][10][clarification needed]
See also
References
- ^ Iyer, Vivek (2006). "Proc. IEEE Eng Med Biol Soc". Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference. Suppl. Cardiovascular Research Center, Massachusetts General Hospital: IEEE: 6761–4. doi:10.1109/IEMBS.2006.260941. PMID 17959506.
{{cite journal}}:|contribution=ignored (help); Cite has empty unknown parameter:|coeditors=(help); Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Liu, N (July–August 2008). "Catecholaminergic polymorphic ventricular tachycardia". Progress in Cardiovascular Diseases. 51 (1): 23–30. doi:10.1016/j.pcad.2007.10.005. PMID 18634915.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ a b Wilde, Arthur (2008-05-08). "Left cardiac sympathetic denervation for catecholaminergic polymorphic ventricular tachycardia". New England Journal of Medicine. 358 (19): 2024–9. doi:10.1056/NEJMoa0708006. PMID 18463378. Retrieved 2008-12-17.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ "Interview with Michael J. Ackerman, M.D., Ph.D." (PDF). Hannah Wernke Memorial Foundation. Retrieved 2009-02-09. [dead link]
- ^ Napolitano, Carlo (May 2007). "Diagnosis and treatment of catecholaminergic polymorphic ventricular tachycardia" (PDF). Heart Rhythm. 4 (5): 675–8. doi:10.1016/j.hrthm.2006.12.048. PMID 17467641. Retrieved 2008-12-17.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) [dead link] - ^ Wehrens XH, Marks AR (2004). "Sudden unexplained death caused by cardiac ryanodine receptor (RyR2) mutations". Mayo Clin. Proc. 79 (11): 1367–71. doi:10.4065/79.11.1367. PMID 15544013.
{{cite journal}}: Unknown parameter|month=ignored (help) [dead link] - ^ Sumitomo, Naokata (January 2003). "Catecholaminergic polymorphic ventricular tachycardia: electrocardiographic characteristics and optimal therapeutic strategies to prevent sudden death". Heart. 89 (1): 66–70. doi:10.1136/heart.89.1.66. PMC 1767500. PMID 12482795.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Watanabe, Hiroshi (2009-04-01). "Flecainide prevents catecholaminergic polymorphic ventricular tachycardia in mice and humans". Nature Medicine. 15 (4): 380–383. doi:10.1038/nm.1942. PMC 2904954. PMID 19330009. Retrieved 2009-05-04.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help) - ^ Hughes, Sue (2008-05-07). "Denervation successfully treats catecholaminergic polymorphic ventricular tachycardia". HeartWire. WebMD. Retrieved 2008-12-17.
{{cite news}}: Cite has empty unknown parameter:|coauthors=(help) - ^ Scott, P.A. (October 2008). "Successful treatment of catecholaminergic polymorphic ventricular tachycardia with bilateral thoracoscopic sympathectomy". Heart Rhythm. 5 (10): 1461–1463. doi:10.1016/j.hrthm.2008.07.007. PMID 18760972.
{{cite journal}}: Unknown parameter|coauthors=ignored (|author=suggested) (help)
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
- Nakajima T, Kaneko Y, Taniguchi Y; et al. (1997). "The mechanism of catecholaminergic polymorphic ventricular tachycardia may be triggered activity due to delayed afterdepolarization". Eur Heart J. 18 (3): 530–1. PMID 9076398.
{{cite journal}}: Explicit use of et al. in:|author=(help); Unknown parameter|month=ignored (help)CS1 maint: multiple names: authors list (link) - 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