What Is the First-Line Medication for Angina Attacks?

When experiencing an angina attack, the first-line medication recommended is nitroglycerin. This drug is widely used due to its rapid action in alleviating chest pain and improving blood flow to the heart. Below is a detailed explanation of how nitroglycerin works and why it may not always provide immediate relief.

How Nitroglycerin Helps During an Angina Attack

1. Reduces Myocardial Oxygen Demand and Increases Oxygen Supply: Nitroglycerin helps balance the heart's need for oxygen by reducing the workload on the heart while simultaneously improving oxygen delivery to the cardiac muscles. This dual effect is key in relieving angina symptoms.

2. Dilates Coronary Arteries: The medication works by expanding the coronary arteries, thereby reducing vascular resistance and enhancing blood flow through the coronary circulation. This improved flow helps deliver more oxygen-rich blood to the heart muscle.

3. Lowers Preload on the Heart: Nitroglycerin also dilates peripheral veins, which reduces the volume of blood returning to the heart. This decreases the heart's workload by lowering the end-diastolic volume, chamber pressure, and ventricular wall tension.

4. Reduces Afterload and Myocardial Demand: In addition to venous dilation, nitroglycerin has a mild effect on arterial dilation, which reduces the resistance the heart must pump against. This further lowers the heart's oxygen requirements and overall stress on the cardiovascular system.

Why Nitroglycerin May Not Relieve Chest Pain

1. Improper Use or Expired Medication: One common reason nitroglycerin may not work is due to expired tablets or dry mouth, which prevents the drug from dissolving properly under the tongue. In such cases, chewing the tablet can help speed up absorption and effectiveness.

2. Possibility of a Heart Attack: If chest pain persists despite taking nitroglycerin, it may indicate a more serious condition such as a myocardial infarction (heart attack). In these situations, immediate medical attention is crucial to prevent further complications.