Patients with cardiac disease and chronic kidney disease are admitted to our emergency unit with signs and symptoms of severe heart failure more and more frequently. Resistance to high-dose loop diuretics imposes the use of renal replacement therapy. We treated a group of these patients with personalized bicarbonate dialysis, deciding the number and frequency of treatment sessions according to the patient's clinical conditions. Heart failure can be classified as mainly diastolic or systolic. Results show that bicarbonate dialysis is effective and well tolerated, primarily in the treatment of patients with prevalently diastolic heart failure. Patients with prevalently systolic heart failure have a worse prognosis.