Heart surfaces are not clearly anatomically defined but arbitrary determined in the context of the heart orientation, that is the relation of the heart to other organs. Different sources mention 3 or 5 heart surfaces and there seems to be no "official" agreement about this.
Most sources (Dartmouth College, Gray's Anatomy for Students 2004...) agree about at least 3 surfaces:
- Anterior (or sternocostal)
- Inferior (or diaphragmatic)
- Left pulmonary
Many sources (TeachMeAnatomy, KenHub...) mention additional 2 surfaces:
- Posterior (or base)
- Right pulmonary
The reasons for disagreement:
- The heart base may not be considered a distinct surface (as in the picture).
- The right pulmonary and anterior (sternocostal) surface are often considered one surface.

Picture: Heart surfaces (source: Echo Class 101)