What is Arrhythmogenic Right Ventricular Dysplasia / Cardiomyopathy?

心律失常性右心室发育不良/心肌病(ARVD/C)是一种罕见的家族性疾病，可引起室性心动过速和年轻的心源性猝死, apparently healthy individuals. The clinical hallmark of the disease is ventricular arrhythmias, arising predominantly from the right ventricle. 该疾病的病理特征是右心室心肌纤维脂肪替代.

What causes ARVD/C?

ARVD/C is caused by mutations in genes that encode desmosomal proteins. These proteins are involved with cell-to-cell adhesion. This important observation helps explain why ARVD/C is more common in athletes, and the delayed onset of the disease.

What are the symptoms of ARVD/C?

Symptoms of ARVD/C include:

• Arrhythmias-心跳时间或模式的异常，表现为心跳加速, skipping heartbeat, palpitations or fluttering sensation
• Premature Ventricular Contractions-当电信号从心脏的下腔(心室)开始时，出现的额外的或不规则的心跳
• Ventricular Tachycardia (VT)– a series of rapid heartbeats, originating in the ventricle. 这种情况可能只持续几次，也可能持续并导致危及生命的心律失常. VT can cause weakness, nausea, vomiting and lightheadedness, as well as feelings of a racing or skipping heart.
• Syncope– Also referred to as fainting or a sudden loss of consciousness
• Heart failure-很少患者的首发症状是与右心衰相关的症状，包括虚弱, foot and ankle swelling (peripheral edema), fluid build-up in the abdomen (ascites), as well as arrhythmic symptoms.
• Sudden cardiac arrest– In some patients, the first sign of ARVD/C is sudden cardiac arrest, 心脏停止跳动，停止向身体其他器官输送血液. This can result in death if not treated within minutes.

How is ARVD/C diagnosed?

ARVD/C的诊断是基于满足一组考虑到ECG异常的特定标准, arrhythmias, structural abnormalities and tissue characteristics, as well as family history and genetics. In 1994, 一个国际工作组提出了ARVD/C的临床诊断标准, based on these various categories. These criteria were very specific to ARVD/C, however they lacked sensitivity in diagnosing milder or atypical presentations. 这些诊断标准在2010年进行了修订，现在纳入了技术和遗传学方面的进展. Information from electrocardiograms (ECGs), signal-averaged ECGs, exercise stress tests, Holter monitors, echocardiograms, MRIs, 在应用诊断标准时，家族史和基因检测是重要的. View a comparison chart of the ARVD/C diagnosis criteria for 1994 and 2010.

The Diagnostic Criteria for ARVD/C

A definite diagnosis ARVD/C包括下列不同类别的标准选项:

• Two major criteria, or
• One major and two minor criteria, or
• Four minor criteria

A borderline diagnosis consists of the following criteria options from different categories:

• One major and one minor criteria, or
• Three minor criteria

A possible diagnosis consists of the following criteria options from different categories:

• One major criteria, or
• Two minor criteria

Testing

There is no single test that can either establish or exclude ARVD/C. The criteria that is used to determine ARVD/C is a physical exam, family history, various cardiac tests and genetic information. Tests may include:

• Electrocardiogram
• Signal-Averaged Electrocardiogram
• 24-hour Holter Monitor
• Exercise Stress Test
• Echocardiogram
• Cardiac Magnetic Resonance Imaging (MRI)
• Cardiac Computed Tomography (CT)
• Genetic Testing
• Electrophysiology Study
• Right Ventriculogram (RV angiogram)
• Cardiac Biopsy

How is ARVD/C treated?

Treatment options vary by patient, and are based on a patient’s cardiac test results, medical history and the presence or absence of genetic mutations. The three most common treatments for arrhythmias are medication, implantable cardioverter defibrillators (ICDs) and catheter ablation.

Medication

药物可以用来减少发作次数和心律失常的严重程度. Medications alter the electrical properties of the heart in one of two ways:

• Directly: The medications affect the electrical currents in the heart
• 间接:药物，如-受体阻滞剂阻断肾上腺素的作用或改善血液流向心脏.

受体阻滞剂可以降低心率、血压和肾上腺素的影响. They are a safe and commonly used type of medication.

如果患者在接受受体阻滞剂治疗后仍出现室性心动过速, antiarrhythmic medications, such as sotolol or amiodarone may be recommended. ace抑制剂也可能有助于减少心脏负荷和预防心力衰竭的发展. 请记住，所有的药物都有副作用，而且每年都有新的药物被开发出来.

Implantable Cardioverter Defibrillator (ICD)

Implantable cardioverter defibrillators are commonly used to treat patients with ARVD/C. 这些设备持续监测心跳，如果出现不规则的心跳或持续快速的心律，就会自动向心脏发出轻微的电击. This may cause a momentary discomfort, which is described by some patients as being “kicked in the chest.”

ICDs also can function as pacemakers and can treat both slow and fast rhythms. 它们应该每三到六个月检查一次，可能需要每四到六年更换一次.

Catheter Ablation

To treat ARVD/C with catheter ablation, 对引起心律失常的心脏部位进行定位并烧灼(烧)以破坏组织. 这种侵入性手术在电生理实验室进行，可以减少心律失常发作的频率.

Traditional catheter ablation, called endocardial ablation, treats the muscle in the inside surface of the heart. 导管穿过腿部的静脉，然后进入心脏，在那里有一个心律失常的区域，并被破坏. 最近，一种很有前途的消融技术被称为心外膜消融. In this technique, the outside of the heart is treated. Many ARVD/C arrhythmias come from the outside of the heart. 在心外膜消融中，导管从胸骨下进入心脏周围的囊. 心外膜消融对于治疗ARVD/C患者的心律失常是非常有效的, this is a complicated procedure. 我们建议在有使用这种心外膜入路治疗ARVD/C患者经验的中心进行手术.

导管消融不是ARVD/C的最终治疗方法，因为它是一种进行性疾病. Catheter ablation can help reduce the need for ICD therapy. 在进行导管消融手术前，患者与医生仔细讨论导管消融的风险和益处是很重要的.

What is the prognosis for ARVD/C?

Some patients will have a stable functioning heart for decades, 而其他人可能有心律失常，需要改变药物或消融. 研究表明，大多数ARVD/C患者的长期前景相对较好. 很少有患者出现如此严重的功能障碍或频繁发作的室性心动过速，以至于可能需要进行心脏移植.

Differential Diagnosis

需要与ARVD/C区分的主要情况是源于流出道的特发性室性心动过速. Ventricular tachycardia can be exactly the same, but there is no structural abnormality of the heart, 不像ARVD/C的情况，通常有心室扩张, abnormal contraction or reduced function. 右心室流出道心动过速比ARVD/C更常见，见于年轻人, otherwise healthy people. The treatment is either with medications or with catheter ablation.