Background

Cardiac Syndrome X is also known as Microvascular Angina or Microvascular Dysfunction. It is a cardiac disease which can cause chest pain or angina pectoris. It does not cause blockage in coronary arteries. Cardiac Syndrome X is difficult to diagnose because coronary arteries do not have severe blockage. 

It is important to note that Cardiac Syndrome X is not the preferred name. The preferred name should be Microvascular Angina or Microvascular Dysfunction. 

Epidemiology

Cardiac Syndrome X is most common in female than males. According to a study, around 50 to 60 % of patients has diagnosed with angina and non-obstructive coronary arteries. 

The cases increase with age and most commonly observed in postmenopausal females. The age of the females is between 40 to 60 years. Postmenopausal females are at high risk of this diseases than the males.  

Anatomy

Pathophysiology

Cardiac Syndrome X is a condition where endothelium do not function properly. It leads to poor vasodilation and vasoconstriction. It affects the blood flow in coronary microvasculature. It causes structural and functional abnormalities in small coronary arteries and arterioles. This includes thickening of blood vessel walls, abnormal vasoconstriction, and decreased dilation ability. Microvascular abnormalities reduce the oxygen flow to heart muscle. This can cause ischemia and angina-like symptoms. Patients with Cardiac Syndrome X also experience sense of pain. This can increase the chain of pain without affecting the coronary artery. 

Etiology

Factors which are associated with this disease are like hormonal factors and inflammations. In postmenopausal females, hormonal changes lead to Cardiac Syndrome X. After the menopause, estrogen level gets decreased. This can affect the endothelium and small coronary blood vessels. 

Severe inflammation is associated with the cardiovascular disease. It damages blood vessel and affect the endothelium function. It can also lead to microvascular abnormalities. 

Other risk factors which are associated with Cardiac Syndrome X are like hypertension, diabetes, dyslipidemia, obesity, smoking, and a family history of coronary artery disease. This can affect the endothelium function. It can also lead to microvascular abnormalities. 

Genetics

Prognostic Factors

Patients who are suffer from the Cardiac syndrome X have a good long term prognosis. With proper treatment, many patients are recovering from the symptoms. Treatment includes medications, changes in lifestyle and procedures to increase the blood flowto heart. 

Clinical History

Cardiac syndrome X is a normal disease. This can cause chest pain similar to angina. It does not lead to heart attack or major cardiac disease. Patient experience chain pain during exercise and rest. The pain usually retrosternal and radiates to the left arm. 

Cardiac syndrome X is common is females. It is caused by affecting microvessels. These vessels provide oxygen and nutrients to heart. This can lead to chest pain without affecting obstructive coronary artery disease. 

Physical Examination

Cardiac syndrome X examinations exclude conditions like cardiac abnormalities, such as murmurs or irregular rhythms. It provides information related to cardiovascular health of the patients. 

In some cases. Patients may have peripheral artery disease (PAD). It affects blood flow in the legs and arms. The symptoms include low pulse, cool skin, and slow wound healing. Inflammation can lead to microvascular dysfunction. In females, hormonal factors are examined. 

Age group

Associated comorbidity

Associated activity

Acuity of presentation

Differential Diagnoses

• Anderson Fabry Disease 
• Takotsubo Heart Disease 
• Percutaneous Coronary Intervention 

Laboratory Studies

Imaging Studies

Procedures

Histologic Findings

Staging

Treatment Paradigm

Beta-Blockers 

Beta blockers like propranolol, nebivolol, and carvedilol are used to treat cardiac syndrome X. 75% of the patients are showing improvement with these treatments. Newer third-generation beta-blockers like carvedilol and nebivolol provide more benefit because of their endothelial vasodilatory action. They promote vasodilation in the endothelium. This can lead to regulate the blood flow and heart perfusion and enhance the outcome of cardiac syndrome X. Propranolol, carvedilol, and nebivolol beta blockers are studying thoroughly in the management of cardiac syndrome X. They show a major efficacy to the affected people. 

Calcium Channel Blockers 

Calcium Channel Blockers are an alternative treatment for beta-blockers. Calcium Channel Blockers include nifedipine, verapamil, and diltiazem. This can increase the tolerance of exercise and reduce angina. Studies have concluded that beta blocker are more effective than Calcium Channel Blockers. 

Anti-anginal Medications 

Anti-anginal Medications are alternative treatment for beta-blockers and calcium channel blockers. Ranolazine is an antianginal medication. It is prescribed for chronic angina. It also prescribed for patients with refractory angina and cardiac syndrome X. 

Statins 

Statin treatment is mainly focused on management of risk factors like high cholesterol levels. It does not directly treat the microvascular component of cardiac syndrome X. It is prescribed to patients who has a cardiovascular risk factor. 

ACE Inhibitors 

Angiotensin-Converting Enzyme (ACE) inhibitors is used to treat the cardiac syndrome X. It contains cardiovascular preventive properties. It reduces the breakdown of the endothelial. This can lead to vasodilation and regulate microvascular ton of coronary vessels. 

Lifestyle Modifications 

Cardiovascular syndrome X is managed by lifestyle changes. This includes exercise, weight management, stop smoking and dietary changes. These changes can improve endothelial function. It is necessary to reduce the adverse effect of cardiovascular disease. Physical activity can improve cardiovascular health, blood flow, and endothelial function. Giving up smoking can improve your vascular health and overall health. Weight control is necessary for those who are obese. 

A healthy diet which contains fruits, vegetables, whole grains, and lean proteins can improve the endothelial function and overall cardiovascular health. Regular physical activity, low in saturated fats, cholesterol, and sodium is suggested and giving up the smoking habit is necessary to manage the cardiac syndrome X. 

by Stage

by Modality

Chemotherapy

Radiation Therapy

Surgical Interventions

Hormone Therapy

Immunotherapy

Hyperthermia

Photodynamic Therapy

Stem Cell Transplant

Targeted Therapy

Palliative Care

Role of Beta-Blockers

Carvedilol 

Carvedilol is a combination of beta and alpha blocking effects. This can help to control the heart rate and blood pressure. It is used for patients who has hypertension and left ventricular dysfunction. 

Nebivolol 

Nebivolol contains nitric oxide-mediated effects. It can also help to control the heart rate and blood pressure. It improves the coronary blood flow. 

Propranolol 

Propranolol can help to control the heart rate and reduce the severity of angina. It is beneficial for patients with tachycardia and excessive sympathetic activity.  

Role of Calcium Channel Blockers

Nifedipine 

Nifedipine can used to reduce the angina symptoms. It can also help to improve the coronary blood flow by vasodilation. A short-act formulations need to be used with precaution due to the risk of reflex tachycardia. 

Verapamil 

Verapamil is used to control the heart rate and improve coronary perfusion. It is beneficial for patients with tachycardia or to avoid the excessive vasodilation. 

Diltiazem 

Diltiazem is used to control the heart rate and improve coronary blood flow. It is beneficial for patients with angina, atrial fibrillation, or tachycardia.  

Role of anti-anginal medications

Ranolazine 

Ranolazine is an anti-anginal medication. It inhibits late sodium currents in cardiac cells. This can lead to reduced levels of intracellular calcium. It helps to improve the utilization of myocardial oxygen and reduces angina symptoms. It can also be prescribed in cases of microvascular angina. 

Role of statins

Rosuvastatin 

Rosuvastatin contains the efficacy to decrease the LDL cholesterol. It has long duration of action and effectiveness. It is effective even at lower doses. It is prescribed in the conditions when a major or severe cholesterol reduction is necessary. It is used for the patients who are high risk of cardiovascular disease and cannot get the normal lipid levels. 

Atorvastatin 

Atorvastatin contains the efficacy to decrease the LDL cholesterol. It has high bioavailability and effective to reduce the cholesterol level. It has long half-life. The dosage should be once a daily orally. It is used for the patients who have hyperlipidemia and high risk of cardiovascular disease. 

Role of ACE Inhibitors

Quinapril 

Quinapril is used for the management of blood pressure. Patients who have hypertension and high risk of cardiovascular disease can take this. The dosage should be once a daily.  

Enalapril 

Enalapril is used for the management of hypertension and left ventricular dysfunction. It controls the blood pressure. It has a long duration of action. 

Medication

Future Trends

Media Gallary

References

https://www.ncbi.nlm.nih.gov/books/NBK578182/#article-142782.s7