My cardiologist is sending me for a echo, having symptoms of pulmonary hypertension, if diagnosed would a slow heart rate and having pacs be connected?

No. Pulmonary hypertension is elevation of the pressures in the lung circulation. There are both primary (intrinsic lung disease) and secondary causes (valve disease, systemic hypertension). An echo is a good place to start as it will help diagnoses the cause and severity of your issue. A slow heart rate is not typically associated with this. Good luck.
Further work up. Pulmonary hypertension should not be diagnosed by echo alone as heart conditions not recommended for treatment by conventional treatment for pah may be the cause. A left and right heart catheterization would be recommended before treatment.