What happens if you have fluid overload in cardiomyopathy (dilated cardiomyopathy)?

From the Guidelines

Fluid overload in patients with dilated cardiomyopathy can lead to exacerbation of heart failure symptoms, including dyspnea, orthopnea, and fatigue.

Treatment Approach

Treatment typically involves administration of loop diuretics, such as furosemide, at an initial dose of 20-40 mg intravenously, which may be increased to 80-160 mg as needed, to reduce pulmonary congestion and edema 1.

• The initial intravenous dose should equal or exceed their chronic oral daily dose and should be given as either intermittent boluses or continuous infusion 1.
• Urine output and signs and symptoms of congestion should be serially assessed, and the diuretic dose should be adjusted accordingly to relieve symptoms, reduce volume excess, and avoid hypotension 1.
• Additionally, vasodilators like nitroglycerin may be used to reduce preload and afterload, with a typical dose of 5-20 mcg/min intravenously, titrated to effect.

Monitoring

• Daily serum electrolytes, urea nitrogen, and creatinine concentrations should be measured during the use of intravenous diuretics or active titration of HF medications 1.
• Daily weight, supine and standing vital signs, fluid input, and output should be monitored as part of daily management 1.
• Assessment of daily electrolytes and renal function should be done while intravenous diuretics or active HF medication titration is being undertaken 1.

From the FDA Drug Label

The principal pharmacological action of Nitroglycerin Injection is relaxation of vascular smooth muscle and consequent dilatation of peripheral arteries and veins, especially the latter Dilatation of the veins promotes peripheral pooling of blood and decreases venous return to the heart, thereby reducing left ventricular end-diastolic pressure and pulmonary capillary wedge pressure (preload). Intravenous nitroglycerin reduced central venous pressure (CVP), right atrial pressure (RAP), pulmonary arterial pressure (PAP), pulmonary-capillary wedge pressure (PCWP), pulmonary vascular resistance (PVR), and systemic vascular resistance (SVR). When these parameters were elevated, reducing them toward normal usually caused a rise in cardiac output

In patients with fluid overload in dilated cardiomyopathy, administration of nitroglycerin (IV) may help reduce preload and afterload, which can lead to a decrease in pulmonary capillary wedge pressure and an increase in cardiac output. The reduction in venous return to the heart can also help alleviate fluid overload. 2

• Key benefits of nitroglycerin (IV) in this context include:
  • Reduction of preload and afterload
  • Decrease in pulmonary capillary wedge pressure
  • Increase in cardiac output
  • Relief of fluid overload symptoms

From the Research

Fluid Overload in Cardiomyopathy (Dilated Cardiomyopathy)

• Fluid overload is a common complication associated with heart failure, including dilated cardiomyopathy, and can lead to symptoms such as edema, pulmonary congestion, and jugular venous distention 3.
• The pathophysiology of congestion in heart failure is complex and involves the dynamics of interstitial and intravascular fluid compartment interactions and fluid redistribution from venous splanchnic beds to central pulmonary circulation 4.
• Exercise-based interventions can help mitigate fluid overload symptoms in patients with heart failure, including dyspnea relief, and may be considered as an effective nonpharmacological therapy 5.
• Tolvaptan, a selective vasopressin V2-receptor antagonist, has been shown to be effective in reducing body weight and improving symptoms of volume overload in heart failure patients, including those with dilated cardiomyopathy 3.
• The "5B" approach, which includes balance of fluids, blood pressure, biomarkers, bioimpedance vector analysis, and blood volume, may be useful in managing fluid overload in heart failure patients and preventing unwanted side effects of treatment 6.
• Ultrasound imaging methods, including imaging of the heart, lungs, kidneys, and venous system, can be used to detect and quantify congestion in heart failure patients, enabling earlier and more accurate diagnosis and facilitating treatment strategies 7.

Management of Fluid Overload

• Diuretics are commonly used to treat fluid overload in heart failure patients, but can cause serum electrolyte imbalances and diuretic resistance 3.
• Extracorporeal therapies, such as ultrafiltration, may be used to remove excess fluid in heart failure patients who are resistant to diuretics 6.
• Careful monitoring of fluid status and adjustment of treatment as needed is crucial to prevent unwanted effects, such as worsening of renal function or other complications 6.
• A target value for fluid status should be set according to objective indicators and biomarkers, and treatment should be individualized to achieve optimal hydration and prevent overhydration or dehydration 6.