Partial atrioventricular canal (PAVC) is a congenital heart defect characterized by an abnormality in the structural organization of the heart, resulting in atrioventricular septal insufficiency, namely, abnormal formation of the atrioventricular valve cusps. There is usually a combination of a single atrioventricular valve and two thick ventricular septa. This defect is most often diagnosed in children, including newborns, and may present with a number of clinical symptoms, such as shortness of breath, cyanosis, chest pain, and growth retardation. The pathology may cause the development of heart failure and other complications that require intensive medical intervention.
History of the disease and interesting historical facts
The first mentions of heart defects, including partial atrioventricular canal, can be traced back to ancient texts. Significant advances in the diagnosis and treatment of such diseases became possible only with the development of cardiology as a science in the 19th and 20th centuries. In the 1940s, researchers began actively studying echocardiography, which subsequently allowed for more accurate detection of cardiac anatomy anomalies, including atrioventricular septal insufficiency. In the 1970s, the advent of modern surgical techniques began a new era in the treatment of PAVC, allowing patients to live a full life. Interestingly, the development of heart transplantation in the late 20th century also contributed to the understanding of the mechanics and general pathophysiology of defects such as PAVC, including through the exchange of surgical experiences between specialists.
Epidemiology
According to various epidemiological data, the incidence of partial atrioventricular canal is approximately 4–8% of all congenital heart defects. Depending on the population, this figure may vary, with the prevalence in neonates reaching approximately 1 in 1,500–2,500 live births. Partial atrioventricular canal is more common in women than in men, with a ratio of approximately 3:1. The disease may also be associated with other cardiac anomalies, such as Down syndrome and other chromosomal abnormalities, increasing the risk of developing PAVK in these patient groups.
Genetic predisposition to this disease
Partial atrioventricular canal may have a genetic origin, especially if there are cases of such a disease in the family or among close relatives. Studies have shown that mutations in genes such as GATA4, NKX2-5 and TBX5 may play a significant role in the pathogenesis of congenital heart defects, including PAC. These genes are responsible for the regulation of cardiac embryology and are often involved in the mechanisms of cell migration and differentiation during the formation of the cardiovascular system. In addition, chromosomal abnormalities such as trisomy 21 (Down syndrome) have also demonstrated a close association with the development of this defect.
Risk factors for the development of this disease
There are several risk factors that may contribute to the development of partial atrioventricular canal:
- Hereditary predisposition to cardiovascular abnormalities.
- Chromosomal abnormalities (eg, Down syndrome).
- Maternal exposure to toxic or chemical substances during pregnancy, including alcoholism or drug addiction.
- Maternal infectious diseases, such as rubella or influenza, during the first trimesters of pregnancy.
- Maternal metabolic diseases such as diabetes.
Diagnosis of this disease
Diagnosis of partial atrioventricular canal requires a comprehensive examination and may include:
- Main symptoms: shortness of breath, cyanosis, difficulty breathing, fatigue, underdevelopment in childhood.
- Laboratory tests: arterial blood oxygenation level analysis, complete blood count and biochemistry.
- Radiological examinations: chest X-ray to assess the size of the heart and pulmonary vessels.
- Echocardiography: is the main imaging method that allows us to see abnormalities in the structure of the heart and evaluate its function.
- CT or MRI of the heart: may be used for more detailed analysis of specific abnormalities.
- Differential diagnosis: includes exclusion of other forms of heart defects such as a full atrioventricular canal and other anomalies.
Treatment
Treatment for partial atrioventricular canal may be multi-step, including:
- General treatment: supportive care, including physical rehabilitation and regular monitoring of cardiac status.
- Pharmacological treatment: may include diuretics, ACE inhibitors to control heart failure.
- Surgical treatment: Atrioventricular canal repair may require surgery to create a normal valve orifice and correct septal insufficiency.
- Other treatments: In some cases, implantation of a pacemaker or use of techniques to improve blood circulation may be necessary.
List of medications used to treat this disease
The main groups of drugs used for partial atrioventricular canal regurgitation include:
- Diuretics (eg, furosemide) - to control edema and heart failure.
- ACE inhibitors (eg, enalapril) - to reduce the load on the heart and improve the prognosis.
- Beta blockers (eg, metoprolol) - to control heart rate.
- Anticoagulants (eg, warfarin) - to prevent blood clots.
Disease monitoring
Monitoring of a patient with partial atrioventricular canal includes regular examinations and monitoring of:
- Control stages: regular examinations by a cardiologist, echocardiographic studies to assess the functioning of the cardiovascular system.
- Prognosis: With timely treatment and adequate medical and surgical support, most patients can expect a normal life expectancy.
- Complications: Possible consequences include heart failure, blood clots, and risk of infective endocarditis.
Age-related features of the disease
Depending on the patient's age, the manifestations and approaches to treating partial atrioventricular canal may differ:
- Newborns: often require emergency diagnosis and, if necessary, surgical intervention at an early age.
- Children: May exhibit slow growth and increased stress, leading to the need for surgical treatment.
- Adults: often require constant monitoring to avoid somatic complications associated with heart failure.
Questions and Answers
- What are the main symptoms of partial atrioventricular canal? The main symptoms include shortness of breath, cyanosis, fatigue and growth retardation in children.
- How is this disease diagnosed? Diagnostics include echocardiography, radiography, and laboratory tests.
- How is partial atrioventricular canal treated? Treatment may include medication, surgery, and supportive care.
- Is there a genetic predisposition to this disease? Yes, mutations in certain genes can increase the risk of developing partial atrioventricular canal.
- What is the prognosis for patients with partial atrioventricular canal? With adequate medical care, many patients have a good prognosis and can lead full lives.
