Cardiac resynchronisation therapy in patients with left bundle branch block with residual conduction

Benefit of natriuresis and cardiac resynchronisation therapy in acute decompensated heart failure with cardiorenal syndrome and hypernatraemia

A man in his eighties with acute heart failure and cardiorenal syndrome developed severe hypernatraemia with diuresis. In this situation, palliation is often considered when renal replacement therapy is inappropriate. The literature to guide treatment of dysnatraemia in this setting is limited. Diuretics often worsen hypernatraemia and fluid replacement exacerbates heart failure. We describe a successful approach to this clinical Catch-22: sequential nephron blockade with intravenous 5% dextrose. Seemingly counterintuitive, the natriuretic effect of this combination had not previously been compared with diuretic monotherapy for heart failure. Yet this immediately effective strategy generated a high natriuresis-to-diuresis ratio and functioned as a bridge to cardiac resynchronisation therapy (CRT). In conjunction with a low salt diet, CRT facilitated the maintenance of sodium homeostasis and fluid balance. Thus, by improving the underlying pathophysiology (ie, inadequate cardiac output), CRT may enhance the outcomes of patients with cardiorenal syndrome and hypernatraemia.