The normal intracellular pH (pHi) of the heart is around 7.1–7.2. This means that the heart's interior is slightly alkaline, just like the rest of the body. However, during conditions like ischemia (lack of blood flow), the heart's pHi can decrease as protons, lactic acid, and carbon dioxide build up.
It's important to note that the pH of the heart is different from the pH of blood, which typically ranges from 7.35 to 7.45.
Here's a breakdown of why pH is important for the heart:
- Cardiac function: pHi is crucial for proper heart function, including excitation and contraction.
- Electrical activity: Abnormalities in pHi can trigger electrical arrhythmias, potentially leading to heart rhythm problems.
- ATP conservation: Transient acidosis (lower pH) during ischemia can be beneficial as it helps conserve ATP by reducing contractility, the heart's main energy consumer.
The heart's pH is a complex and dynamic variable that plays a critical role in its overall health and function.
