rmal heartbeats DizzinessDecreased appetite Hypertrophic cardiomyopathy presents in a variety of ways.Infants may have: Fast and heavy breathing with feedingsSweating with feedings Lethargy or inactivityPoor weight gain Older children may have:Trouble exercising Chest pain with exercise Palpitations DizzinessPassing out (passing out during exercise is a concern and children should be seen by a car