Introduction
The term “heart failure” often arouses thoughts of left ventricular (LV) dysfunction, as LV dysfunction is the most common cause of heart failure. Nonetheless, in approximately 2% of patients who show clinical signs of heart failure, the primary pathology is rooted in the right side of the heart—the right ventricle, right atrium, and tricuspid valve—without left heart involvement. Various etiologies can contribute to these pathologies, such as right ventricular (RV) dysfunction — due to ischemia, cardiomyopathy, arrhythmia, pulmonary hypertension, congenital abnormalities, pulmonary embolism, or tricuspid valve dysfunction. It is crucial to distinguish that right heart failure (RHF) does not equate to RV impairment. Rather, RV impairment represents one of the potential causes of RHF, resulting in diminished stroke volume.
Managing patients with Right Heart Failure can be challenging, as this population is predominantly elderly individuals with numerous coexisting medical conditions. The risks associated with invasive therapeutic interventions in these patients are substantial. Consequently, before pursuing an invasive procedure, it is imperative to ascertain the precise underlying pathology and carefully weigh the potential outcomes to ensure optimal clinical decision-making.
Difference between Right and left heart failure: Clinical Manifestations
Distinct symptoms and signs may arise depending on whether the left or right side of the heart is primarily involved in heart failure. Left Heart Failure (LHF) is the predominant form, accounting for most heart failure cases. It is characterized by significant fatigue and dyspnea, initially upon exertion and eventually at rest as the disease progresses. Two key features of LHF are orthopnea and Paroxysmal Nocturnal Dyspnea (PND).
Orthopnea refers to the sensation of breathlessness experienced in a recumbent position, which typically alleviates upon sitting or standing. PND, on the other hand, is characterized by episodes of shortness of breath that awaken the patient approximately 1 to 2 hours after sleep and improve upon adopting an upright position. As LHF advances, the filling (diastolic) pressure in the left ventricle and left atrium rises, eventually transmitting this pressure toward the pulmonary circulation, leading to pulmonary congestion, contributing to PND, orthopnea, and in severe cases, pulmonary edema. With further progression, LHF can ultimately overwhelm the right side of the heart, resulting in right ventricular (RV) dilatation and failure. Therefore, LHF is the most common cause of Right Heart Failure (RHF).
Differentiating signs and symptoms in Right vs Left heart failure
As previously noted, in approximately 2% of patients presenting with heart failure signs and symptoms, the primary pathology is confined to the right side, manifesting as isolated RHF. The primary symptoms in these cases include fatigue, abdominal fullness, loss of appetite, and exertional dyspnea — mainly due to reduced RV stroke volume and lung perfusion. Physical findings in RHF include:
- Lung auscultation: In LHF, crackles (rales) may be heard on lung auscultation due to pulmonary congestion and fluid accumulation in the alveoli. In contrast, lung auscultation in isolated RHF is typically unremarkable.
- Hepatomegaly: RHF can cause congestion in the liver, leading to hepatomegaly (enlarged liver), which can be palpable on physical examination. In LHF, hepatomegaly —if present at all— is less prominent.
- Ascites: Ascites, fluid accumulation in the abdominal cavity, is more commonly observed in RHF.
- Hepatojugular reflux: This clinical sign, characterized by increased jugular venous pressure when the liver is pressed gently, is more commonly seen in RHF due to elevated central venous pressure.
Hallmark physical findings of RHF are distended neck veins (elevated Jugular Venous Pressure or JVP) and peripheral pitting edema, particularly in the lower limbs. In the initial stages, the absence of frequent PND, orthopnea, and pulmonary edema episodes is pivotal for differentiating isolated RHF from the more common LHF.Â
Tricuspid Valve Regurgitation: Right Heart Failure and reduced stroke volume
Right heart failure (RHF) is a clinical syndrome arising from impaired function of the right side of the heart, which reduces effective stroke volume—the volume of blood pumped from the right ventricle towards the pulmonary circulation with each heartbeat. The term “towards the pulmonary circulation” is crucial in defining the effectiveness of stroke volume.
In the case of tricuspid regurgitation (TR), blood is ejected from the right ventricle into the right atrium during systole rather than flowing towards the intended direction of pulmonary circulation. Although echocardiogram may show preserved right ventricular function, the contractions are inefficient, as a significant portion of the blood volume is being ejected in the wrong direction. This results in a reduced stroke volume. As TR becomes more severe, the effective stroke volume decreases even further, leading to more pronounced symptoms of right heart failure.
TR has three main categories of causes
- Primary TR: This form of TR arises from valve abnormalities, such as those resulting from rheumatic fever or endocarditis.
- Secondary (Functional) TR: Often caused by right ventricular dysfunction or dilation, secondary TR leads to a coaptation defect in which the valve leaflets are pulled apart.
- Pacemaker-induced TR: Cardiac implantable electronic devices (CIED) or pacemaker-induced TR occurs due to lead-related damage to the valve or interference with its function.
Pacemaker-induced TR should be considered in cases where a patient presents with typical symptoms of right heart failure and severe TR on cardiac imaging but with an apparently preserved or mildly impaired right ventricular function on echocardiogram. A high index of suspicion is crucial to avoid missing this important diagnosis.
Mechanisms of CIED-related Tricuspid Valve Regurgitation
CIED-related tricuspid valve regurgitation (TR) has been described in various publications and case series. The proposed mechanisms for CIED-related TR can be broadly categorized into implantation-related, pacing-related, and device-mediated factors.
- Implantation-related: The risk of TR and damage to the tricuspid valve may vary depending on the operator’s technique used to implant the device. Although the evidence is not robust, some techniques may cause more damage to the valve than others. For example, the “prolapsing” technique is thought to be less risky compared to the direct crossing of the tricuspid valve.
- Pacing-related: Several studies have linked right ventricular (RV) pacing to worsening tricuspid valve regurgitation. Alterations in RV geometry due to pacing are suggested as a possible mechanism. However, the available data is not as strong as that observed for the worsening of mitral regurgitation with pacing.
- Lead-mediated: Pacemaker or defibrillator leads can interfere with tricuspid valve function through various mechanisms, such as impingement, adhesion, entrapment, entanglement, and perforation, as illustrated in Table-1.
Table-1: Lead-related mechanisms of tricuspid valve regurgitation
| Impinging | When the lead slack creates a pressure point that comes into contact with a valve leaflet, it interferes with the leaflet's function. In this case, the lead has not adhered to the leaflet but merely exerts pressure on it. |
| Adhering | When the lead becomes attached to a leaflet, most likely a result of long-term impingement |
| Entrapment | When the lead becomes trapped within a leaflet due to fibrosis. Since this process involves fibrosis, it typically occurs much later after pacemaker insertion. |
| Entangling | When the lead is trapped in the sub-valvular apparatus |
| Perforation | When the lead punctures a leaflet during implantation. Lead perforation tends to be more common in the septal leaflet |
The terminology used to describe various lead-related issues can be quite complex. Chronologically, impingement, adhesion, and entrapment can be considered as a continuum of events. Initially, the lead impinges on a leaflet (resting loosely without adhesion). Over time, the lead becomes adhered to the leaflet more firmly. Eventually, fibrotic tissue progressively encases the lead, burying it deep within the tissue and resulting in lead entrapment. The terms entanglement and perforation are relatively more straightforward in their description.
Case Presentation
Background
As a former professional racewalker, he could easily race-walk 15 km up to five years ago but was now struggling to carry a few grocery bags from the shops to his car. His only medication was warfarin for long-standing Atrial Fibrillation (AF), diagnosed in 2000. He had a pacemaker inserted for Complete Heart Block in 2005. In 2012, he underwent a box change and a new ventricular lead insertion. The reason for the new ventricular lead was unclear from the available medical records. An Echocardiogram in 2011 showed low-normal left ventricle function, trivial to mild tricuspid regurgitation, and a mildly dilated left atrium.
In 2013, one year after the box change and insertion of the new lead, he reported to his cardiologist that “his general health has gone downhill”; however, he could not provide more specific details. His echocardiogram showed mild tricuspid regurgitation, mild-to-moderate pulmonary hypertension, and moderately dilated atria. Unfortunately, due to an extended overseas trip, he was lost to follow-up for nearly five years until 2019. His symptoms gradually worsened during this period and were initially dismissed as “age-related complaints” by his family and primary healthcare providers. He did not have diabetes, hypertension, or other significant comorbidities and had never smoked. His renal function was normal.
Physical findings
On presentation in 2019, his blood pressure was 130/70 mmHg, and his pulse was 70 bpm. His lungs were mostly clear to auscultation, and only mild pitting edema was present at the ankles. However, A prominent feature in his physical exam, visible from across the room, was a distended and pulsatile jugular vein, as shown in Video-1.
Video-1: Lancisi sign: severely raised JVP with prominent C–V waves of severe tricuspid regurgitation in the upright position.
ECG and Chest X-Ray:
The ECG and chest X-ray are displayed below. The rhythm is paced with underlying Atrial Fibrillation, and the atrial lead is capped. In the apical chest X-ray, the right ventricular (RV) lead is attached to the inferior border of the right ventricle, while in the lateral view, the lead is positioned at the posterior aspect of the right ventricle. Overall, the chest X-ray suggests an infero-posterior position of the lead.
ECG – typical paced rhythm morphology and underlying atrial fibrillation
Apical CXR – Severely enlarged heart with RV lead fixed in far inferior border of the right ventricle
Lateral CXR – RV lead in the most posterior segment of the right ventricle
Echocardiogram:
The echocardiogram revealed grossly dilated atria. Left ventricular function was around 50%, primarily due to dyssynchronous septal wall motion. Mild mitral regurgitation was also observed. The right ventricle was moderate-severely dilated, but the right ventricular function was relatively preserved. Severe, eccentric tricuspid regurgitation originated from the postero-septal aspect (commissure) of the tricuspid valve, where the pacemaker lead was visible. Upon examining the images, it is apparent that the pacemaker lead is anchored to the posterior wall, displaying minimal movement.
Video-2: Low-normal and dyssynchronous LV function (Paced). RV dilated.
Video-3: Mild MR, sclerotic AV with satisfactory function and reasonable RV function.
Video-4: RV inflow view: with septal (S) and Anterior (A) leaflets in view.
Video-5: TR jet originating close to the septal leaflet and posteriorly directed.
Video-6: Short axis view showing reasonable LV function and dilated RV
Video-7: Apical view showing mild-moderate MR
Video-8: RV outflow view showing septal and posterior leaflets.Â
Video-9: Significant TR originating from the postero-septal leaflets juncture
Video-10: Apical view showing grossly dilated atria and dilated RV. Lead slack can be seen attached to the RA wall.
Video-11: TR jet starting slightly above the coaptation line. This is usually a hint in favour of lead-induced TR.
Video-12: as the probe tilted more, the TR jet becomes more prominent with the CS in view, indicating the involvement of the posterior and inferior part of the TV
Video-13: probe tilted posteriorly with the CS in view. S and P leaflets are visible. jet originates posteriorly, near the postero-septal commissure, well above coaptation line.
Video-14: Subcostal view showing that the lead is fixated and has minimal movements which mimic the movement of the right ventricle.Â
Video-15: Origin of the eccentric TR jet, next to the lead (lead-hugging) in subcostal view.
Video-16: Severely dilated IVC with no respiratory collapse, which explains the raised JVP.
The Challenge: TR due to long-term Atrial Fibrillation or Pacemaker-Lead related
If there was no device-lead present, in this case, the TR could be attributed to the dilated tricuspid annulus, which is a common finding in patients with long-standing atrial fibrillation and severely dilated atria. However, a crucial question arises when a device lead is present; is the lead responsible for the regurgitation’s “presence” or “severity”? Answering this question has obvious clinical and management implications, especially in a patient with signs and symptoms of right heart failure.
Clues to differentiate between lead-related TR vs other causes
- Review of previous imaging studies: It is essential to review them before the device implantation to ascertain the absence of severe TR.
- Timeline of symptoms: Consider the onset and progression of the patient’s symptoms in relation to the device implantation and lead replacement. If the patient’s symptoms significantly worsened after these interventions, it might suggest a causal relationship between the lead and TR.
- Response to medical therapy: Discuss whether the patient has had any response to medical therapy for heart failure, such as diuretics. If the patient’s symptoms remain unresponsive to medical management, it could further suggest that the device lead plays a role in TR and right heart failure. In this case, our patient’s symptoms did not respond to diuretics.
- Echocardiographic findings: TR jet and lead characteristics in echocardiographic images can help immensely. CIED lead-related TR jet is usually eccentric and tends to hug the lead, and the jet can start well above the leaflet’s coaptation line (Figure-3). The lead is usually off-centred, fixed to a leaflet, and has minimal motion (Video-14). An entrapped lead is closely associated with a leaflet and moves in concert; the leaflet puppeteers the lead. Based on these pictures and the characteristics of the TR jet, the likely cause of the pathology is either an “entrapped lead” or a “perforated leaflet”.
Tricuspid valve leaflet localisation on 2D echocardiogram
The tricuspid valve is a complex structure with significant variability in its anatomy. Typically, it consists of three leaflets – anterior, posterior, and septal – but variations with two, four, or even five leaflets can also be found. The septal leaflet is the longest, the anterior leaflet is the largest, and the posterior leaflet is the smallest. To accurately localize the affected leaflets on echocardiogram, the tricuspid valve should be thoroughly interrogated in every available view. However, the three most essential 2D echocardiography views for examining the tricuspid valve are the right ventricular (RV) inflow, short-axis, and apical 4-chamber views.
Best Echocardiogram views to localise tricuspid valve leaflets
Septal and anterior leaflets are visible in the RV inflow view (video-4). In apical 4-chamber view, if the left ventricular outflow tract (LVOT) is visible, the septal and anterior leaflets can be seen; conversely, if the coronary sinus (CS) is visible, the septal and posterior leaflets are in view (Figure-4). In the parasternal short-axis view (SAX), the anterior leaflet, which is the largest tricuspid valve leaflet, is usually visible. If two leaflets are present in this view, they are most likely the septal and anterior leaflets (video-8).
Identifying the affected leaflets is crucial for determining the appropriate management strategy, especially when considering interventions such as tricuspid valve repair or replacement. A comprehensive leaflet morphology, mobility, and coaptation assessment help clinicians choose the most suitable approach.
When available, incorporating 3D echocardiography into the evaluation process can further enhance the understanding of the tricuspid valve’s complex anatomy and improve diagnostic accuracy. While 2D echocardiography helps localize tricuspid valve leaflets, 3D echocardiography can provide even greater detail about the valve’s anatomy and function. This advanced imaging modality allows for a more accurate assessment of leaflet pathology and can help confirm the findings from 2D echocardiography.
CT coronary angiogram and CIED-induced tricuspid regurgitation
CT Coronary Angiogram (CTCA) is an often-overlooked imaging modality that can provide invaluable information in determining the course of a device lead and localizing the underlying pathology. As transcatheter tricuspid valve device implantations become more advanced, CTCA has emerged as an exceptional tool for examining the tricuspid valve and its surrounding structures. The following video demonstrates the capability of CT to accurately localize the position of the CIED-lead in relation to the tricuspid valve. This additional imaging method can significantly enhance the diagnostic process and contribute to a more comprehensive understanding of lead-induced tricuspid regurgitation.
Video-17: The video above illustrates that the pacemaker lead is positioned in an infero-posterior location, which is consistent with the CXR images. Ideally, the lead should be situated in the centre of the tricuspid valve, between the commissures. This observation serves as another clue, suggesting that the CIED-lead likely plays a role in developing severe tricuspid regurgitation.
Surgical findings and progress
Based on the comprehensive information gathered from multiple imaging modalities and the patient’s symptoms, surgery was offered as a viable option, given that the right ventricular function remained well-preserved despite dilatation. During the surgical procedure, it was confirmed that the pacemaker lead had perforated the most inferior part of the septal leaflet adjacent to the postero-septal commissure. The lead was found embedded in the leaflet and firmly fixed in place. Additionally, the atrial portion of the lead had become fibrosed in place at the cavo-atrial junction.
The patient underwent a successful bioprosthetic tricuspid valve replacement with excellent results. Three months post-surgery, he exercised for 9 minutes and 34 seconds on the Bruce Protocol during rehabilitation. Remarkably, three years after the procedure, he continues to walk daily for 5-10 kilometres without any cardiac limitations.
Conclusion:
In this case, numerous learning points emerge, highlighting the importance of taking patients’ concerns seriously and not dismissing their symptoms as merely “age-related.” The case demonstrates the complexity of diagnosing lead-related tricuspid valve regurgitation (TR) and the need for a comprehensive approach to differentiating it from other causes of TR, such as atrial fibrillation-induced TR.
This case underscores the potential benefits of timely surgical correction in select patients with lead-related TR before right ventricular dysfunction develops. Multimodality imaging and a collaborative team approach are essential for accurate diagnosis and for creating an effective treatment plan.
Recent advances in transcatheter tricuspid valve replacement have opened new possibilities for less invasive therapy, offering a promising alternative to traditional surgical intervention. As this field continues to evolve, many patients may benefit from these less invasive treatments, improving their quality of life and potentially increasing longevity. By carefully considering each patient’s unique situation and acting promptly, healthcare providers can significantly impact the lives of those affected by lead-related TR.
Refrences:
- Yong-Jin Kim. Determinants of Surgical Outcome in Patients With Isolated Tricuspid Regurgitation. Circulation. 2009;120:1672–1678Â
- Karima Addetia, et al. Cardiac Implantable Electronic Device Lead-Induced TR. JACC Cardiovasc Imaging. 2019 Apr;12(4):622-63
Pravin V. Patil. Next Steps in Modeling the Tricuspid Valve. Circulation: Cardiovascular Imaging. 2017;10:e005949Â
