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Monitoring of heart failure: comparison of left atrial pressure with intrathoracic impedance and natriuretic peptide measurements in an experimental model of ovine heart failure.

Rademaker MT, Charles CJ, Melton IC, Richards AM, Frampton CM, Siou J, Qu F, Eigler NL, Gutfinger D, Troughton RW - Clin. Sci. (2011)

Bottom Line: In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations.Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF.ALAP provides an estimate of LAP that may be clinically useful.

View Article: PubMed Central - PubMed

Affiliation: Christchurch Cardioendocrine Research Group, University of Otago, Christchurch, New Zealand. miriam.rademaker@otago.ac.nz

ABSTRACT
Monitoring of HF (heart failure) with intracardiac pressure, intrathoracic impedance and/or natriuretic peptide levels has been advocated. We aimed to investigate possible differences in the response patterns of each of these monitoring modalities during HF decompensation that may have an impact on the potential for early therapeutic intervention. Six sheep were implanted with a LAP (left atrial pressure) sensor and a CRT-D (cardiac resynchronization therapy defibrillator) capable of monitoring impedance along six lead configuration vectors. An estimate of ALAP (LAP from admittance) was determined by linear regression. HF was induced by rapid ventricular pacing at 180 and 220 bpm (beats/min) for a week each, followed by a third week with daily pacing suspensions for increasing durations (1-5 h). Incremental pacing induced progressively severe HF reflected in increases in LAP (5.9 ± 0.4 to 24.5 ± 1.6 mmHg) and plasma atrial (20 ± 3 to 197 ± 36 pmol/l) and B-type natriuretic peptide (3.7 ± 0.7 to 32.7 ± 5.4 pmol/l) (all P<0.001) levels. All impedance vectors decreased in proportion to HF severity (all P<0.001), with the LVring (left ventricular)-case vector correlating best with LAP (r2=0.63, P<0.001). Natriuretic peptides closely paralleled rapid acute changes in LAP during alterations in pacing (P<0.001), whereas impedance changes were delayed relative to LAP. ALAP exhibited good agreement with LAP. In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations. Natriuretic peptides respond rapidly to acute LAP changes. Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF. ALAP provides an estimate of LAP that may be clinically useful.

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Related in: MedlinePlus

Expanded view of LAP, natriuretic peptide and LVring-case and RVcoil-case admittance vector responses in six sheep during acute on/off changes in pacingPacing was turned off for a 1-h period on day 14, increasing incrementally each day to a 5-h period on day 18. Values shown are means ± S.E.M.
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Figure 4: Expanded view of LAP, natriuretic peptide and LVring-case and RVcoil-case admittance vector responses in six sheep during acute on/off changes in pacingPacing was turned off for a 1-h period on day 14, increasing incrementally each day to a 5-h period on day 18. Values shown are means ± S.E.M.

Mentions: During the third week of pacing (days 14–18), acute interruptions in pacing for increasing durations of time (1–5 h sequentially over the 5 days) induced rapid falls (within an hour) in LAP averaging 9.1 ± 0.1 mmHg (P<0.001) (Figure 4). Recommencement of pacing on each day restored LAP promptly to levels observed prior to pacing termination. Changes in plasma natriuretic peptide concentrations over this 5-day period largely paralleled those of LAP, with ANP and BNP falling on average by 137 ± 8 and 20.9 ± 1.5 pmol/l, respectively (both P<0.001), following disruption of pacing. However, pacing resumption resulted in a striking peak and ‘overshoot’ in the first hour followed by a re-establishment of ANP and BNP at levels observed prior to pacing cessation.


Monitoring of heart failure: comparison of left atrial pressure with intrathoracic impedance and natriuretic peptide measurements in an experimental model of ovine heart failure.

Rademaker MT, Charles CJ, Melton IC, Richards AM, Frampton CM, Siou J, Qu F, Eigler NL, Gutfinger D, Troughton RW - Clin. Sci. (2011)

Expanded view of LAP, natriuretic peptide and LVring-case and RVcoil-case admittance vector responses in six sheep during acute on/off changes in pacingPacing was turned off for a 1-h period on day 14, increasing incrementally each day to a 5-h period on day 18. Values shown are means ± S.E.M.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2990201&req=5

Figure 4: Expanded view of LAP, natriuretic peptide and LVring-case and RVcoil-case admittance vector responses in six sheep during acute on/off changes in pacingPacing was turned off for a 1-h period on day 14, increasing incrementally each day to a 5-h period on day 18. Values shown are means ± S.E.M.
Mentions: During the third week of pacing (days 14–18), acute interruptions in pacing for increasing durations of time (1–5 h sequentially over the 5 days) induced rapid falls (within an hour) in LAP averaging 9.1 ± 0.1 mmHg (P<0.001) (Figure 4). Recommencement of pacing on each day restored LAP promptly to levels observed prior to pacing termination. Changes in plasma natriuretic peptide concentrations over this 5-day period largely paralleled those of LAP, with ANP and BNP falling on average by 137 ± 8 and 20.9 ± 1.5 pmol/l, respectively (both P<0.001), following disruption of pacing. However, pacing resumption resulted in a striking peak and ‘overshoot’ in the first hour followed by a re-establishment of ANP and BNP at levels observed prior to pacing cessation.

Bottom Line: In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations.Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF.ALAP provides an estimate of LAP that may be clinically useful.

View Article: PubMed Central - PubMed

Affiliation: Christchurch Cardioendocrine Research Group, University of Otago, Christchurch, New Zealand. miriam.rademaker@otago.ac.nz

ABSTRACT
Monitoring of HF (heart failure) with intracardiac pressure, intrathoracic impedance and/or natriuretic peptide levels has been advocated. We aimed to investigate possible differences in the response patterns of each of these monitoring modalities during HF decompensation that may have an impact on the potential for early therapeutic intervention. Six sheep were implanted with a LAP (left atrial pressure) sensor and a CRT-D (cardiac resynchronization therapy defibrillator) capable of monitoring impedance along six lead configuration vectors. An estimate of ALAP (LAP from admittance) was determined by linear regression. HF was induced by rapid ventricular pacing at 180 and 220 bpm (beats/min) for a week each, followed by a third week with daily pacing suspensions for increasing durations (1-5 h). Incremental pacing induced progressively severe HF reflected in increases in LAP (5.9 ± 0.4 to 24.5 ± 1.6 mmHg) and plasma atrial (20 ± 3 to 197 ± 36 pmol/l) and B-type natriuretic peptide (3.7 ± 0.7 to 32.7 ± 5.4 pmol/l) (all P<0.001) levels. All impedance vectors decreased in proportion to HF severity (all P<0.001), with the LVring (left ventricular)-case vector correlating best with LAP (r2=0.63, P<0.001). Natriuretic peptides closely paralleled rapid acute changes in LAP during alterations in pacing (P<0.001), whereas impedance changes were delayed relative to LAP. ALAP exhibited good agreement with LAP. In summary, impedance measured with an LV lead correlates significantly with changes in LAP, but exhibits a delayed response to acute alterations. Natriuretic peptides respond rapidly to acute LAP changes. Direct LAP, impedance and natriuretic peptide measurements all show promise as early indicators of worsening HF. ALAP provides an estimate of LAP that may be clinically useful.

Show MeSH
Related in: MedlinePlus