- Email: [email protected]
Reply to the Editor—Retaining vascular access during lead replacement
LETTERS TO THE EDITOR Letter to the Editor— Retaining vascular access during lead replacement I read with interest the article by Mendenhall1 in the November 2011 issue of HeartRhythm. The author describes a novel technique for retaining vascular access during lead replacement. This is absolutely a critical issue when dealing with lead removal or upgrading procedures in which a new lead(s) must be implanted. The author mentions the possibility of retaining vascular access by using the laser-assisted tract technique as the only currently available alternative to his new description.2 However, it should be acknowledged that Antonelli et al3 previously described a simple and elegant method for the same purpose. This method consists of inserting the tip of a guide wire between the insulation layer and the conductor after retraction of the lead to the superior vena cava. Then the lead with the guide wire attached to the insulator is advanced until the guide wire gets into the superior vena cava, and at this point the guide wire is retracted and released in the vein lumen. Although the new technique described by Mendenhall is defined as simple and rapid, I think it is probably more time-consuming and complex than the previous one. I have personally used the method described by Antonelli et al on several occasions, and it takes no more than 1–2 minutes to get the vascular access. Obviously, the differences between these 2 techniques have to be proven, but the initial description by Antonelli and colleagues should be acknowledged. Meanwhile, I thank Dr Mendenhall for giving us another alternative method to overcome the challenging issue of getting vascular access during lead replacement. Oscar Cano, MD [email protected] Electrophysiology Section Cardiology Department Hospital Universitari i Politècnic La Fe Valencia, Spain
References 1. 2.
3.
Mendenhall GS. A straightforward, reliable technique for retaining vascular access during lead replacement. Heart Rhythm 2011;8:1812–1814. Bracke FA, Meijer A, van Gelder LM. Use of a laser sheath to obtain venous access in pacemaker lead-related obstruction without extraction of the lead. Europace 2002;4:67– 68. Antonelli D, Freedberg NA, Turgeman Y. Pacing and defibrillation lead exchange without vein puncture. Pacing Clin Electrophysiol 2009;32:588 –590.
Reply to the Editor—Retaining vascular access during lead replacement I greatly appreciate the letter of Dr Cano regarding the acknowledgment of an alternate technique to maintain vas-
cular access by insertion of a wire between the insulation and conductor of a lead, well described by Antonelli et al.1 This lead-splitting technique, along with the laser-exchange sheath2 or nonsplittable sheath,3 is most certainly another facile way of retaining vascular access during lead replacement. The choice between the two non–laser-assisted techniques1,3 should depend on the clinical situation. Both require a freely mobile lead in the circulation, and both require lead sacrifice prior to start, thus committing the operator to replacement. Antonelli’s lead-splitting technique may require a bit more functional lead length as sufficient lead must be removed from the circulation to make a slit and then readvanced into the circulation with the embedded wire. With the sheath technique, the lead can often be held as a “rail,” useful only if a smaller fraction of the lead may remain in the circulation. This may be clinically encountered if the lead is damaged where it becomes intravascular, such as with fractures near the retaining sleeve owing to flex-point metal fatigue, overzealous tightening of retaining suture, or other crush effect, where the integrity of this portion of the lead to readvance into the circulation past this point may be questionable, or if the fracture prevents admission of a stylet. In this case, cutting the lead at the fracture point and using the sheath technique may provide a better option. In extremely thin leads, such as more recent 4F left ventricular leads or the Fineline lead family (Boston Scientific, Natick, MA), cutting of the insulation to insert a wire may be somewhat difficult because of the smaller size of the lead and thus the sheath technique may be preferred. Theoretically, in lumenless leads such as the Medtronic SelectSecure 3830 (Medtronic Corporation, Minneapolis, MN), the sheath technique may be the only possibility for exchange via advancement over the held lead, while leadsplitting wire retention would not be available because of the inability to advance the lead on its own into the vasculature on a stiff stylet. I have not had opportunity to test this in vivo. My sheath technique may be at a disadvantage relative to Dr Antonelli’s technique due to the time it takes to set up and the requirement to use a stiffer nonsplittable sheath as an intermediate step. Moreover, it is possible that different leads now or in the future may be “in between” sizes and not fit snugly on any sheath, giving rise to problems owing to sheath buckling when attempting to enter the vasculature. Finally, for success with both techniques, there should ideally be a minimum of tissue, especially scar tissue or parts of the fibrous capsule, between the lead and the entry to the vein, which may impede access. This is especially
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Heart Rhythm, Vol 9, No 3, March 2012
true for the sheath technique, which is more vulnerable to burring and buckling of the sheath if there is significant sigmoidal tunneling through fibrotic tissue or if there was puncture of the costoclavicular ligament. In this case, the lead-splitting technique may provide a better option if the wire can be accommodated or, if possible, dissection along the lead nearer to the insertion to the vein could be carefully performed. It should be recognized that in some cases such as this, however, with a nonideal entry path into the vein or with significant “hinge points” or kinking, it may be useful to reevaluate and obtain de novo access if at all possible, as any forces that caused one lead failure may persist and lead to another. Vascular access is simultaneously mundane and challenging; like a fractal, the closer one looks, the more nuance one can keep on finding in the decisions and techniques required to maximize lead longevity and minimize associated morbidity. These principles are increasingly referred to as “lead management.” Close attention to all forces that act on any inserted lead, and having an abundance of techniques at our disposal for access and replacement, will only lead to improved outcomes for our patients. G. Stuart Mendenhall, MD [email protected] UPMC Cardiovascular Institute University of Pittsburgh Pittsburgh, Pennsylvania
References 1. 2.
3.
Antonelli D, Freedberg NA, Turgeman Y. Pacing and defibrillation lead exchange without vein puncture. Pacing Clin Electrophysiol 2009;32:588 –590. Bracke FA, Meijer A, van Gelder LM. Use of a laser sheath to obtain venous access in pacemaker lead-related obstruction without extraction of the lead. Europace 2002;4:67– 68. Mendenhall GS. A straightforward, reliable technique for retaining vascular access during lead replacement. Heart Rhythm 2011;8:1812–1814.
Letter to the Editor— Average T-wave alternans in ambulatory electrocardiogram recordings in patients with heart failure I read with joy the contribution of Monasterio et al,1 published ahead of print in HeartRhythm on October 21, 2011, in which the authors report on the long-term average T-wave alternans (TWA) activity from 24-hour ambulatory Holter electrocardiograms (ECGs) recorded in 650 patients with heart failure. They found that after a median follow-up of 48 months, the survival rate was significantly higher in the group of patients who reached a value of ⬍3.7 V in their averaged TWA. Using an averaged metric for TWA is refreshing. Indeed, this reader has expressed for sometime concern about reports using one TWA metric, reflecting the maximum TWA value from Holter ECG recordings, while it is obvious to readers of such tests that there is a large range in the amplitude of T waves over the course of 24 hours. There must be a way to evaluate the contribution of this range of T-wave ampli-
tudes or to be exact the amplitude of the JT intervals, since this was used by the authors for their calculations, and the TWA (eg, the voltage-time integral). In other words, is there a relationship of the series of values of TWA and the JT integral obtained during the 24 hours in Holter ECG recordings in the individual patients? Another thought that arises from the authors’ decision to use an integration of X, Y, and Z ECG leads for generating the TWA is whether that way they have lost information deriving from the “regionality” of TWA displayed by different regions of the heart in patients with ischemic cardiomyopathy and previous myocardial infarction, as shown previously. John E. Madias, MD, FACC, FAHA [email protected] Mount Sinai School of Medicine, New York University and Division of Cardiology Elmhurst Hospital Center, New York, New York
Reference 1.
Monasterio V, Laguna P, Cygankiewicz I, et al. Average T-wave alternans activity in ambulatory ECG records predicts sudden cardiac death in patients with chronic heart failure. Heart Rhythm Oct 21, 2011. Epub ahead of print.
Letter to the Editor– Average T-wave alternans activity in ambulatory electrocardiogram records: Commentary on the relationship with T-wave amplitude and T-wave alternans regionality We thank Dr Madias for his kind comments1 and the interest in our paper,2 and we would like to comment on the points raised. Dr Madias’ first question was about the relationship between T-wave alternans (TWA) and the amplitude of the JT segment. We agree that when studying local TWA amplitudes, the question of whether TWA depends on the T-wave amplitude could be of interest, as it might indicate that adjusting local TWA values to T-wave amplitudes could improve the value of TWA clinical indices. With the approach proposed in our work, however, the effect of T-wave amplitudes on TWA indices is no longer a one-to-one relationship. The indices proposed in our paper depend not only on local TWA amplitudes but also on the percentage of time with TWA in a 24-hour period. This means, for example, that the index of average alternans would be low for electrocardiograms presenting high-amplitude TWA during a small percentage of time. This particular framework, therefore, is not appropriate to determine the exact influence of JT amplitudes on TWA indices. Dr Madias also raised the question of whether the use of a multilead combination produces a loss of information on the “regionality” of TWA. We would like to clarify that it is not the case. As we explain in the paper, the way of combining X, Y, Z electrocardiographic leads is not predefined, but is specifically computed for each segment in order to maximize the visibility of TWA in the resulting lead. The combined lead can thus be interpreted as a derived lead
References 1. 2.
3.
Mendenhall GS. A straightforward, reliable technique for retaining vascular access during lead replacement. Heart Rhythm 2011;8:1812–1814. Bracke FA, Meijer A, van Gelder LM. Use of a laser sheath to obtain venous access in pacemaker lead-related obstruction without extraction of the lead. Europace 2002;4:67– 68. Antonelli D, Freedberg NA, Turgeman Y. Pacing and defibrillation lead exchange without vein puncture. Pacing Clin Electrophysiol 2009;32:588 –590.
Reply to the Editor—Retaining vascular access during lead replacement I greatly appreciate the letter of Dr Cano regarding the acknowledgment of an alternate technique to maintain vas-
cular access by insertion of a wire between the insulation and conductor of a lead, well described by Antonelli et al.1 This lead-splitting technique, along with the laser-exchange sheath2 or nonsplittable sheath,3 is most certainly another facile way of retaining vascular access during lead replacement. The choice between the two non–laser-assisted techniques1,3 should depend on the clinical situation. Both require a freely mobile lead in the circulation, and both require lead sacrifice prior to start, thus committing the operator to replacement. Antonelli’s lead-splitting technique may require a bit more functional lead length as sufficient lead must be removed from the circulation to make a slit and then readvanced into the circulation with the embedded wire. With the sheath technique, the lead can often be held as a “rail,” useful only if a smaller fraction of the lead may remain in the circulation. This may be clinically encountered if the lead is damaged where it becomes intravascular, such as with fractures near the retaining sleeve owing to flex-point metal fatigue, overzealous tightening of retaining suture, or other crush effect, where the integrity of this portion of the lead to readvance into the circulation past this point may be questionable, or if the fracture prevents admission of a stylet. In this case, cutting the lead at the fracture point and using the sheath technique may provide a better option. In extremely thin leads, such as more recent 4F left ventricular leads or the Fineline lead family (Boston Scientific, Natick, MA), cutting of the insulation to insert a wire may be somewhat difficult because of the smaller size of the lead and thus the sheath technique may be preferred. Theoretically, in lumenless leads such as the Medtronic SelectSecure 3830 (Medtronic Corporation, Minneapolis, MN), the sheath technique may be the only possibility for exchange via advancement over the held lead, while leadsplitting wire retention would not be available because of the inability to advance the lead on its own into the vasculature on a stiff stylet. I have not had opportunity to test this in vivo. My sheath technique may be at a disadvantage relative to Dr Antonelli’s technique due to the time it takes to set up and the requirement to use a stiffer nonsplittable sheath as an intermediate step. Moreover, it is possible that different leads now or in the future may be “in between” sizes and not fit snugly on any sheath, giving rise to problems owing to sheath buckling when attempting to enter the vasculature. Finally, for success with both techniques, there should ideally be a minimum of tissue, especially scar tissue or parts of the fibrous capsule, between the lead and the entry to the vein, which may impede access. This is especially
1547-5271/$ -see front matter © 2012 Heart Rhythm Society. All rights reserved.
e6
Heart Rhythm, Vol 9, No 3, March 2012
true for the sheath technique, which is more vulnerable to burring and buckling of the sheath if there is significant sigmoidal tunneling through fibrotic tissue or if there was puncture of the costoclavicular ligament. In this case, the lead-splitting technique may provide a better option if the wire can be accommodated or, if possible, dissection along the lead nearer to the insertion to the vein could be carefully performed. It should be recognized that in some cases such as this, however, with a nonideal entry path into the vein or with significant “hinge points” or kinking, it may be useful to reevaluate and obtain de novo access if at all possible, as any forces that caused one lead failure may persist and lead to another. Vascular access is simultaneously mundane and challenging; like a fractal, the closer one looks, the more nuance one can keep on finding in the decisions and techniques required to maximize lead longevity and minimize associated morbidity. These principles are increasingly referred to as “lead management.” Close attention to all forces that act on any inserted lead, and having an abundance of techniques at our disposal for access and replacement, will only lead to improved outcomes for our patients. G. Stuart Mendenhall, MD [email protected] UPMC Cardiovascular Institute University of Pittsburgh Pittsburgh, Pennsylvania
References 1. 2.
3.
Antonelli D, Freedberg NA, Turgeman Y. Pacing and defibrillation lead exchange without vein puncture. Pacing Clin Electrophysiol 2009;32:588 –590. Bracke FA, Meijer A, van Gelder LM. Use of a laser sheath to obtain venous access in pacemaker lead-related obstruction without extraction of the lead. Europace 2002;4:67– 68. Mendenhall GS. A straightforward, reliable technique for retaining vascular access during lead replacement. Heart Rhythm 2011;8:1812–1814.
Letter to the Editor— Average T-wave alternans in ambulatory electrocardiogram recordings in patients with heart failure I read with joy the contribution of Monasterio et al,1 published ahead of print in HeartRhythm on October 21, 2011, in which the authors report on the long-term average T-wave alternans (TWA) activity from 24-hour ambulatory Holter electrocardiograms (ECGs) recorded in 650 patients with heart failure. They found that after a median follow-up of 48 months, the survival rate was significantly higher in the group of patients who reached a value of ⬍3.7 V in their averaged TWA. Using an averaged metric for TWA is refreshing. Indeed, this reader has expressed for sometime concern about reports using one TWA metric, reflecting the maximum TWA value from Holter ECG recordings, while it is obvious to readers of such tests that there is a large range in the amplitude of T waves over the course of 24 hours. There must be a way to evaluate the contribution of this range of T-wave ampli-
tudes or to be exact the amplitude of the JT intervals, since this was used by the authors for their calculations, and the TWA (eg, the voltage-time integral). In other words, is there a relationship of the series of values of TWA and the JT integral obtained during the 24 hours in Holter ECG recordings in the individual patients? Another thought that arises from the authors’ decision to use an integration of X, Y, and Z ECG leads for generating the TWA is whether that way they have lost information deriving from the “regionality” of TWA displayed by different regions of the heart in patients with ischemic cardiomyopathy and previous myocardial infarction, as shown previously. John E. Madias, MD, FACC, FAHA [email protected] Mount Sinai School of Medicine, New York University and Division of Cardiology Elmhurst Hospital Center, New York, New York
Reference 1.
Monasterio V, Laguna P, Cygankiewicz I, et al. Average T-wave alternans activity in ambulatory ECG records predicts sudden cardiac death in patients with chronic heart failure. Heart Rhythm Oct 21, 2011. Epub ahead of print.
Letter to the Editor– Average T-wave alternans activity in ambulatory electrocardiogram records: Commentary on the relationship with T-wave amplitude and T-wave alternans regionality We thank Dr Madias for his kind comments1 and the interest in our paper,2 and we would like to comment on the points raised. Dr Madias’ first question was about the relationship between T-wave alternans (TWA) and the amplitude of the JT segment. We agree that when studying local TWA amplitudes, the question of whether TWA depends on the T-wave amplitude could be of interest, as it might indicate that adjusting local TWA values to T-wave amplitudes could improve the value of TWA clinical indices. With the approach proposed in our work, however, the effect of T-wave amplitudes on TWA indices is no longer a one-to-one relationship. The indices proposed in our paper depend not only on local TWA amplitudes but also on the percentage of time with TWA in a 24-hour period. This means, for example, that the index of average alternans would be low for electrocardiograms presenting high-amplitude TWA during a small percentage of time. This particular framework, therefore, is not appropriate to determine the exact influence of JT amplitudes on TWA indices. Dr Madias also raised the question of whether the use of a multilead combination produces a loss of information on the “regionality” of TWA. We would like to clarify that it is not the case. As we explain in the paper, the way of combining X, Y, Z electrocardiographic leads is not predefined, but is specifically computed for each segment in order to maximize the visibility of TWA in the resulting lead. The combined lead can thus be interpreted as a derived lead