Management of Complications of a Fulminant Varicella Zoster Virus (VZV) Associated with Myocarditis and Left Ventricular Thrombus Under VA-ECMO: A Case Report of a Novel Thrombectomy Technique with Pulsed Irrigation and Review of Left and Right Ventricular Unloading Techniques

1. Introduction

Myocarditis represents a challenging diagnosis, particularly in critically ill patients [1,2]. Varicella Zoster Virus (VZV)–induced myocarditis is an uncommon but potentially severe cause of myocardial inflammation [3,4,5]. The situation becomes more complex when myocardial dysfunction progresses to cardiogenic shock requiring mechanical circulatory support.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is often used in the setting of witnessed cardiac arrest to provide systemic perfusion and oxygenation. However, the increased afterload from ECMO flow and the absence of native left ventricular ejection can lead to stasis within the left ventricle and subsequent thrombus formation. This case illustrates the complex management of viral myocarditis, mechanical circulatory support, and surgical intervention.

2. Introduction

Myocarditis represents a challenging diagnosis, particularly in critically ill patients [1,2]. Varicella Zoster Virus (VZV)–induced myocarditis is an uncommon but potentially severe cause of myocardial inflammation[3,4,5]. The situation becomes more complex when myocardial dysfunction progresses to cardiogenic shock requiring mechanical circulatory support.

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is often used in the setting of witnessed cardiac arrest to provide systemic perfusion and oxygenation. However, the increased afterload from ECMO flow and the absence of native left ventricular ejection can lead to stasis within the left ventricle and subsequent thrombus formation. This case illustrates the complex management of viral myocarditis, mechanical circulatory support, and surgical intervention.

3. Case Presentation

A 50 years old female patient was admitted after an out-of-hospital witnessed cardiac arrest due to ventricular fibrillation, a shockable rhythm. Following successful resuscitation, she remained in refractory cardiogenic shock despite optimal medical support. Peripheral VA-ECMO was promptly initiated[6]. On admission, polymerase chain reaction (PCR) testing revealed the presence of Varicella Zoster Virus (VZV) DNA in her blood, suggesting active viremia that was treated with acyclovir[4,7]. Coronary angiography was performed and revealed normal coronary arteries (Figure 1), thereby ruling out an ischemic cause of her cardiac arrest.

At this stage, a provisional diagnosis of fulminant Varicella Zoster Virus (VZV)–associated myocarditis was made, based on clinical presentation and laboratory findings.

As the next step following VA-ECMO initiation, protecting the heart from excessive distension becomes paramount[8,9]. Strategies for left ventricular (LV) unloading[10], which have been associated with improved survival, must be considered early. Despite maximal support, including intra-aortic balloon pump (IABP)[11] placement and creation of a Rashkind atrial septostomy[12], the patient exhibited complete absence of aortic valve opening and persistent left ventricular distension. (Figure 2)

Despite an adequately maintained anticoagulation profile, monitored through serial anti-Xa assays a transthoracic echocardiogram revealed a large, organized thrombus occupying the apex and mid-left ventricular (LV) cavity. (Figure 3)

While on mechanical ventilation, a structured sedation vacation permitted a reassuring neurological assessment. Upon sedation withdrawal, the patient demonstrated spontaneous eye opening, visual tracking, and appropriate response to simple commands. These findings confirmed intact brainstem function and supported the decision to continue full intensive care measures[13].

A multidisciplinary team, including specialists in cardiac surgery, infectious diseases, intensive care, and cardiology, opted for a surgical left ventricular thrombectomy[14]. The goals were to prevent systemic thromboembolism and enable potential recovery of left ventricular function. Should myocardial recovery prove unattainable, expedited evaluation for heart transplantation was planned as a secondary intervention, necessitating transfer to a specialized center by aerial transportation while on ECMO support.

It is noteworthy that the island of Martinique, where the patient initially presented, situated in the Lesser Antilles of the West Indies, functions as a regional hub for cardiac surgery. However, it currently lacks facilities for heart transplantation.

4. Surgical Management

The patient was taken to the operating room. A median sternotomy was performed, and upon opening the pericardium, a pressurized, hemorrhagic effusion consistent with tamponade was observed. After systemic heparinization, cardiopulmonary bypass (CPB) was established via bicaval venous cannulation and femoral arterial cannulation.

Moderate hypothermia was initiated, and the aorta was clamped. Myocardial protection was achieved using retrograde hyperkalemic blood cardioplegia delivered through the coronary sinus, minimizing the risk of dislodging thrombus that could occur with antegrade delivery. Upon initial aortotomy, no visible thrombus was detected in the aortic root, allowing for the safe addition of ostial antegrade cardioplegia. The left ventricle was thoroughly irrigated and suctioned by a pulse irrigator (Figure 4) after manual debulking of the thrombus, which was done via the aortic valve to remove residual debris and optimize visualization.

Subsequently, a transseptal left atriotomy was performed, allowing direct access to the LV via the mitral valve. Copious amounts of thrombi were removed, and the cavity was thoroughly irrigated with the pulse irrigator. The Rashkind septostomy previously done was closed.

An LV apical muscular biopsy was taken and sent for pathology for analysis. A 22 Fr cannula was placed through the apex of the LV and connected to the venous line of the ECMO circuit to provide continuous decompression [15]. The LV vent cannula was partially clamped by a Hoffman tubing clamp to control flow and avoid recirculation.

The aortic clamping time was 49 minutes, time that was necessary to clean all the residual thrombi. The heart resumed spontaneous sinus rhythm with successful defibrillation. CPB was discontinued after 98 minutes, and ECMO flow resumed.

5. Discussion

5.1. VZV Myocarditis

VZV is a DNA herpesvirus classically associated with varicella (chickenpox) and herpes zoster (shingles). Although it more commonly affects the skin and nervous system, VZV can cause myocarditis via direct viral invasion or immune-mediated mechanisms. Few cases have been documented, mostly in immunocompromised or elderly patients. Given the increased risk of severe complications in this population, current guidelines recommend administration of a booster dose of the varicella zoster vaccine starting at age 65 to enhance immunity and reduce the likelihood of viral reactivation.[16]

Our patient had no rash or neurological symptoms, but VZV DNA positivity in blood strongly suggests systemic reactivation. Cardiac catheterization was normal, ruling out ischemic causes and supporting a diagnosis of viral myocarditis.

5.2. Thrombus Formation Under ECMO

Thrombus formation in the LV under ECMO occurs due to:[17]

• Increased afterload from retrograde aortic flow
• Absence of native LV ejection
• Poor myocardial contractility (as in myocarditis)
• Inadequate anticoagulation
• Tamponade or external compression

Blood stasis in a non-contractile LV leads to a prothrombotic environment. In the presence of viable myocardium and preserved end-organ function, surgical decompression and thrombectomy may facilitate recovery.

6. Left Ventricular Unloading Techniques Under VA-ECMO

Effective LV unloading prevents thrombus formation, improves coronary perfusion, and reduces pulmonary edema. Various techniques exist; we present in this table four common techniques:

Table 1. A comparative table of LV unloading methods.

Technique	Type	Access	Effectiveness	Notes
Intra-Aortic counter pulsation Balloon (IACPB)	Percutaneous	Femoral artery	Low to moderate	Reduces afterload, promotes aortic valve opening
LV Apical Vent	Surgical	Sternotomy/ thoracotomy	Very high	Direct decompression, requires surgical access
Atrial Transseptal septostomy (Rashkind)	Percutaneous	Atrial septum	Low to moderate	Simple, often inadequate alone
ECMELLA (ECMO + Impella)	Hybrid	Dual access	Very high	Expensive, effective unloading and perfusion

Table 1. A comparative table of LV unloading methods.

Technique	Type	Access	Effectiveness	Notes
Intra-Aortic counter pulsation Balloon (IACPB)	Percutaneous	Femoral artery	Low to moderate	Reduces afterload, promotes aortic valve opening
LV Apical Vent	Surgical	Sternotomy/ thoracotomy	Very high	Direct decompression, requires surgical access
Atrial Transseptal septostomy (Rashkind)	Percutaneous	Atrial septum	Low to moderate	Simple, often inadequate alone
ECMELLA (ECMO + Impella)	Hybrid	Dual access	Very high	Expensive, effective unloading and perfusion

7. Right Ventricular Failure and Unloading Techniques Under VA-ECMO

RV failure can coexist with LV dysfunction or develop as a complication of ECMO[18,19,20]. It contributes to elevated right atrial pressure, hepatic congestion, and reduced ECMO drainage[21]. Right ventricular (RV) unloading is increasingly recognized as a critical adjunct in biventricular failure or when RV dysfunction occurs during VA-ECMO

Management Strategies:

Management of right ventricular (RV) failure during VA-ECMO requires a multimodal approach tailored to the hemodynamic profile and underlying pathology. Initial strategies include volume optimization to reduce preload and alleviate RV strain, followed using pulmonary vasodilators such as inhaled nitric oxide or sildenafil to decrease pulmonary vascular resistance. In cases of persistent RV dysfunction, inotropic support with agents like milrinone or dobutamine can enhance contractility. For patients with severe RV overload or persistent congestion, surgical pulmonary artery venting may provide effective decompression. In more advanced scenarios, right ventricular assist devices (RVADs) offer direct mechanical support to the failing RV. Additionally, conversion to a veno-veno-arterial (VVA) ECMO configuration may be considered with venous cannulas in the superior and inferior vena cava to augment both RV and LV unloading while maintaining systemic perfusion.

Table 2. A comparative table of RV unloading methods.

Technique	Type	Access/Method	Effectiveness	Notes
Volume Optimization	Medical	Diuretics, fluid restriction	Moderate	First-line approach; risk of hypoperfusion
Pulmonary Vasodilators	Pharmacologic	Inhaled NO, Sildenafil	Variable	Reduce pulmonary pressure; monitor for hypotension
Inotropes	Pharmacologic	Milrinone, Dobutamine	Moderate	Improve RV contractility; watch for arrhythmias
Pulmonary Artery Venting	Surgical	Via PA cannula	High	Direct RV unloading; requires surgical access
RVAD (Right Ventricular Assist Device)	Mechanical	Percutaneous or surgical	Very High	Direct support of RV output; technically complex
VVA-ECMO Configuration	ECMO Adjustment	Dual ECMO cannulas	High	Supports both ventricles; may need additional flow regulation

Table 2. A comparative table of RV unloading methods.

Technique	Type	Access/Method	Effectiveness	Notes
Volume Optimization	Medical	Diuretics, fluid restriction	Moderate	First-line approach; risk of hypoperfusion
Pulmonary Vasodilators	Pharmacologic	Inhaled NO, Sildenafil	Variable	Reduce pulmonary pressure; monitor for hypotension
Inotropes	Pharmacologic	Milrinone, Dobutamine	Moderate	Improve RV contractility; watch for arrhythmias
Pulmonary Artery Venting	Surgical	Via PA cannula	High	Direct RV unloading; requires surgical access
RVAD (Right Ventricular Assist Device)	Mechanical	Percutaneous or surgical	Very High	Direct support of RV output; technically complex
VVA-ECMO Configuration	ECMO Adjustment	Dual ECMO cannulas	High	Supports both ventricles; may need additional flow regulation

8. ECMO Setup and Technical Parameters

The patient was placed on VA-ECMO using a Cardiohelp HLS Advanced 7.0 system, with cannulas sizing was as follows:

• Arterial Cannula: 17 Fr
• Venous Cannula: 25 Fr
• Reperfusion Cannula (Femoral): 6 Fr
• Heparin Dose on Insertion: 5,000 IU

Body Surface Area (DuBois Formula): BSA (m²) =1.85

Cannula sizing was based on patient’s BSA and hemodynamic targets, with optimal ECMO flow calculated at a cardiac index of 2.4 L/min/m², resulting in a total flow rate of approximately 4.4 L/min. This target was used to ensure adequate systemic perfusion and end-organ oxygenation[22,23].

9. Myocarditis of Probable Viral Origin: Pathology Review

Histological analysis of LV apex biopsy revealed:

• Plurifocal myocyte damage
• Infiltrate rich in T-lymphocytes (CD3+), few B cells (CD20+), rare eosinophils and macrophages (CD68+)
• No granulomas, giant cells, or fungal elements
• Pericardial fluid: fibrinous pericarditis without specific features

These findings are compatible with a lymphocytic myocarditis of probable viral origin. Eosinophils raise the possibility of a drug reaction or parasitic etiology, but the clinical context and positive VZV PCR favor viral myocarditis. Tissue quality limited advanced PCR/metagenomic testing.

10. Conclusion

This case illustrates the rare occurrence of VZV-induced myocarditis presenting with cardiac arrest and evolving LV thrombus formation under VA-ECMO. Early recognition and aggressive management—including surgical thrombectomy and apical venting—are crucial to prevent irreversible myocardial damage or embolic events. Comprehensive LV and RV unloading strategies must be individualized and initiated promptly to optimize outcomes in patients with severe myocardial dysfunction.

Unfortunately, despite these efforts, the patient passed away due to multi-organ failure on postoperative day six.