Aortic Stenosis: A Comprehensive Overview

Introduction

Aortic stenosis is a progressive, potentially life-threatening condition characterized by the narrowing of the aortic valve opening, which impedes blood flow from the left ventricle to the aorta and onward to the rest of the body. It is one of the most prevalent valvular heart diseases, especially in older adults, and its impact reaches far beyond the confines of the heart, often affecting overall health, physical function, and quality of life.

Pathophysiology of Aortic Stenosis

Aortic stenosis occurs when the leaflets of the aortic valve thicken, stiffen, and fuse, reducing the valve area and obstructing blood flow. This increased resistance places a chronic pressure load on the left ventricle, which must work harder to overcome the narrowed opening. Over time, the ventricular muscle thickens (hypertrophy) as a compensatory mechanism, but eventually this leads to reduced cardiac output, heart failure, and other complications.

Causes of Aortic Stenosis

• Congenital: Some people are born with a bicuspid aortic valve (only two leaflets instead of three), which is more prone to stenosis earlier in life.
• Degenerative or Calcific: The most common cause in older adults is age-related calcific degeneration, where calcium deposits accumulate on the leaflets.
• Rheumatic Heart Disease: In developing countries and older populations, a history of rheumatic fever can result in chronic inflammation and scarring of the valve.
• Other Causes: Rarely, conditions such as radiation exposure, endocarditis, or chronic kidney disease may contribute to aortic stenosis.

Risk Factors and Epidemiology

Aortic stenosis primarily affects those over 65 years of age and has a higher prevalence in men than women. Additional risk factors include:

• High blood pressure
• Elevated cholesterol levels
• Smoking
• Diabetes mellitus
• Chronic kidney disease
• Family history of valvular heart disease
• History of rheumatic fever

The incidence of calcific aortic stenosis rises with age, making it an increasing public health concern in aging populations worldwide.

Clinical Presentation

Aortic stenosis may be silent for years, but as the valve narrows and cardiac output diminishes, symptoms begin to appear. The classic triad of symptoms includes:

• Angina (chest pain): Due to increased myocardial oxygen demand and reduced supply.
• Syncope (fainting): Often occurs with exertion as the heart struggles to maintain adequate cerebral perfusion.
• Heart failure symptoms: Dyspnea (shortness of breath), fatigue, and eventually pulmonary edema.

Other signs may include palpitations, dizziness, and, in advanced cases, sudden cardiac death.

Physical Examination and Diagnosis

Physical examination may reveal:

• A systolic, crescendo-decrescendo murmur best heard at the right upper sternal border and radiating to the neck.
• Reduced or delayed carotid pulse (“pulsus parvus et tardus”).
• Signs of left ventricular hypertrophy (displacement of the apex beat).

Diagnosis is confirmed through:

• Echocardiography: The gold standard, providing measurements of valve area, gradients, and ventricular function.
• Electrocardiogram (ECG): May show left ventricular hypertrophy.
• Chest X-ray: Can reveal cardiac enlargement or evidence of pulmonary congestion.
• Cardiac catheterization: Used in certain cases to measure pressures and assess for coronary artery disease prior to surgery.

Severity of Aortic Stenosis

Severity is classified based on aortic valve area and pressure gradients:

• Mild: Valve area >1.5 cm², mean gradient <20 mmHg
• Moderate: Valve area 1.0-1.5 cm², mean gradient 20-40 mmHg
• Severe: Valve area  40 mmHg

Severe cases with symptoms are associated with a poor prognosis without intervention.

Complications

Aortic stenosis can lead to several complications, including:

• Left ventricular failure
• Pulmonary hypertension
• Arrhythmias, such as atrial fibrillation
• Sudden cardiac death
• Endocarditis (infection of the valve)

Management of Aortic Stenosis

Treatment options depend on the severity and symptoms:

Medical Management

• Limitations: No medical therapy can halt or reverse valve narrowing; medications are used to treat symptoms and associated conditions such as hypertension or arrhythmias.
• Close monitoring: Asymptomatic patients with mild or moderate stenosis should have regular follow-ups, including echocardiograms.
• Prevention strategies: Manage risk factors like hypertension, high cholesterol, and diabetes; avoid strenuous activity in severe cases.

Surgical and Interventional Management

• Surgical Aortic Valve Replacement (SAVR): The definitive treatment, indicated for symptomatic severe stenosis or declining left ventricular function. The damaged valve is replaced with a mechanical or bioprosthetic valve.
• Transcatheter Aortic Valve Implantation (TAVI or TAVR): A less invasive alternative for patients at high surgical risk; a new valve is delivered via a catheter, usually through the femoral artery.
• Balloon Valvuloplasty: Primarily used in pediatric or young adult congenital cases; limited efficacy in adults.

Post-operative Care and Prognosis

Successful valve replacement dramatically improves symptoms and survival. Post-operative care includes anticoagulation (for mechanical valves), infection prevention, and regular monitoring. Most patients regain normal activity levels, although long-term follow-up is essential.

Prevention and Early Detection

While many cases are related to aging and cannot be prevented, addressing modifiable risk factors is crucial. Early detection through routine physical exams and cardiac imaging in at-risk populations can help prevent progression and complications.

Living with Aortic Stenosis

Patients with aortic stenosis should educate themselves about their condition, attend regular follow-up appointments, monitor symptoms, and maintain heart-healthy lifestyles. Support from cardiac rehabilitation programs and patient support groups can enhance quality of life.

Nursing Care of Patients with Aortic Stenosis

Nursing Interventions

Activity Management:

• Encourage rest and limit physical activities according to tolerance, as exertion may precipitate symptoms or complications.
• Assist with activities of daily living as needed to reduce cardiac workload.

Oxygen Therapy:

• Administer supplemental oxygen if hypoxia is present or as prescribed.

Medication Administration:

• Administer prescribed medications such as diuretics, beta-blockers, ACE inhibitors, or anticoagulants with careful monitoring for side effects and effectiveness.
• Avoid vasodilators unless specifically prescribed, as they may cause dangerous drops in blood pressure.

Prevention of Complications:

• Monitor for signs of heart failure, arrhythmias, or embolic events.
• Promptly report chest pain, syncope, or acute shortness of breath to the physician.

Skin and Pressure Care:

• Maintain skin integrity by regular repositioning and providing pressure area care, especially in immobilised or elderly patients.

Nutrition:

• Encourage a low-sodium, heart-healthy diet. Monitor for signs of malnutrition, especially in elderly patients.

Patient and Family Education

• Educate the patient and family about the nature of aortic stenosis, symptoms to monitor, and when to seek urgent medical attention (e.g., sudden chest pain, fainting, severe breathlessness).
• Advise on the importance of regular follow-up with a cardiologist, adherence to medication schedules, and lifestyle modifications.
• Discuss the potential need for surgical interventions such as aortic valve replacement or balloon valvuloplasty, explaining procedures and post-operative care as appropriate.
• Promote smoking cessation, moderation of alcohol intake, and weight management.

Psychosocial Support

Aortic stenosis can significantly impact a patient’s quality of life. Nurses should provide emotional support, address anxiety or depression, and facilitate access to counselling services if needed. Involve family members in the care process and encourage open communication about fears or concerns.

Discharge Planning and Follow-Up

• Ensure the patient has a clear understanding of medication regimens and follow-up appointments.
• Provide written instructions on activity levels, dietary recommendations, and warning signs of deterioration.
• Arrange for home nursing care or community health services if indicated, especially for elderly or debilitated patients.

REFERENCES

1. American Heart Association. Aortic Stenosis Overview. https://www.heart.org/en/health-topics/heart-valve-problems-and-disease/heart-valve-problems-and-causes/problem-aortic-valve-stenosis. Last reviewed 5/23/2024. .
2. Aortic Stenosis. In: Crawford MH, Aras M, Sanchez JM, eds. Quick Dx & Rx: Cardiology. McGraw-Hill Education; 2018.
3. Brown KN, Kanmanthareddy A. Ross Procedure for Aortic Valve Replacement. https://pubmed.ncbi.nlm.nih.gov/30725934/. 2023 Feb 13. In: StatPearls [Internet.] Treasure Island (FL): StatPearls Publishing; 2024 Jan.
4. Everett RJ, Clavel MA, Pibarot P, Dweck MR. Timing of intervention in aortic stenosis: a review of current and future strategies. https://pubmed.ncbi.nlm.nih.gov/30030337/. Heart. 2018;104(24):2067-2076.
5. Kogoj P, Devjak R, Bunc M. Balloon aortic valvuloplasty (BAV) as a bridge to aortic valve replacement in cancer patients who require urgent non-cardiac surgery. https://pubmed.ncbi.nlm.nih.gov/24587781. Radiol Oncol. 2014 Jan 22;48(1):62-66.
6. Pujari SH, Agasthi P. Aortic Stenosis. https://pubmed.ncbi.nlm.nih.gov/32491560/. 2023 Apr 16. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan.
7. Singh GK. Congenital Aortic Valve Stenosis. https://pubmed.ncbi.nlm.nih.gov/31086112/. Children (Basel). 2019 May 13;6(5):69.

Stories are the threads that bind us; through them, we understand each other, grow, and heal.

JOHN NOORD

Connect with “Nurses Lab Editorial Team”

I hope you found this information helpful. Do you have any questions or comments? Kindly write in comments section. Subscribe the Blog with your email so you can stay updated on upcoming events and the latest articles.